fix(agent): SignalIngress worker re-entrancy — never block the single consumer on its own post

EffectRunner posts ClassifierVerdictIssued from inside DecisionStepProcessor.ApplyStep,
i.e. on the SignalIngress worker thread. With the bounded channel (256) full, Post's
back-pressure slow path blocked the channel's only consumer as a producer: nothing could
ever drain, every collector Post blocked behind it, and the whole decision/monitoring
pipeline froze silently until the max-lifetime watchdog.

Post now detects a call from the worker thread itself and routes the item to a
worker-local follow-up queue that WorkerLoop drains (iteratively, ahead of the channel)
right after the current item. Same processing path — ordinals, SignalLog, emit,
reduce, ApplyStep — just never blocking. Worker posts are accepted during the Stop
drain too, since the verdict belongs to the step being finished. ReentrantPostCount
exposed for observability/tests.

Tests: full channel + worker post releases a blocked foreign producer and processes the
verdict before the next channel item (fails against the previous code by hanging);
follow-up chain drained in order without recursion; verdict posted during Stop drain is
not lost. Docs: agent/decision-engine.md, agent/overview.md, log.md.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/deploy-mcp.yml

@@ -11,7 +11,11 @@ env:
   ACR_NAME: autopilotmonitoreuacr
   CONTAINER_APP_NAME: autopilotmonitor-mcp
   RESOURCE_GROUP: ${{ secrets.AZURE_MCP_RESOURCE_GROUP }}
-  IMAGE_TAG: ${{ github.sha }}
+  # Unique per RUN, not per commit: the docs corpus is baked into the image, so a
+  # docs-only redeploy at an unchanged code sha must still produce a new image
+  # reference — with a sha-only tag `az containerapp update` saw the same image
+  # and silently created no revision (2026-08-28).
+  IMAGE_TAG: ${{ github.sha }}-${{ github.run_number }}
   HEALTH_URL: https://mcp.autopilotmonitor.com/health
   VERSIONS_CONTAINER: https://autopilotmonitoreu.blob.core.windows.net/versions
   PACKAGE_JSON: src/McpServer/autopilot-monitor-mcp/package.json
@@ -28,8 +32,9 @@ jobs:
       # baked into the image as the search_docs corpus (see the Dockerfile). No
       # token is needed. Checking it out here rather than vendoring it keeps the
       # docs single-sourced — but it also means EDITING THE DOCS DOES NOT UPDATE A
-      # RUNNING SERVER; this workflow must be re-run. /health reports the SHA
-      # captured below so that staleness is checkable.
+      # RUNNING SERVER; this workflow must be re-run (IMAGE_TAG is per run so the
+      # re-run actually rolls a new revision). /health reports the SHA captured
+      # below so that staleness is checkable.
       - name: Check out documentation bundle
         uses: actions/checkout@v7
         with:

docs/agent/cmtrace-time-resolution.md

@@ -94,7 +94,11 @@ batch, the counter reconcile's existing event-partition scan additionally collec
 rest (`CmTraceSkewTripwire`, hooked in `EventIngestProcessor`). If
 `median(Δ_IME) − median(Δ_other)` is a clean 15-minute multiple (residual < 2 min — the
 same constants as the anchoring grid guard above) with ≥ 20 samples over ≥ 3 distinct
-upload batches per side, a `CmTraceTimeSkewRegression` ops event fires (category Agent,
+upload batches per side, and ≥ 80 % of the individual IME deltas (relative to the other
+side's median) themselves sit within 2 min of some grid multiple — added after the 2026-08-28
+soak, when relaunched agents re-tailing the IME log produced one burst holding most of a
+session's IME samples with a continuum of ages whose median hit the grid by chance (7 false
+fires in a week, 0 true) — a `CmTraceTimeSkewRegression` ops event fires (category Agent,
 warning), carrying all numbers plus the session's `sourceOffsetOrigin` histogram.
 Bias-dominated sessions are suppressed (writer-declared offsets cannot be an anchoring
 regression); `measuredWriterOffsetMinutes` is never consulted (sticky after era

docs/agent/decision-engine.md

@@ -216,7 +216,12 @@ Wired by `EnrollmentOrchestrator.Start` (`src/Agent/AutopilotMonitor.Agent.V2.Co
 - `SignalIngress` — bounded queue (256, back-pressure) + **one** worker thread. Per
   signal, in order: assign ordinals → `SignalLog.Append` (durable, *before* reducing;
   append failure ⇒ reducer does not run, no ordinal gap) → `engine.Reduce` →
-  `DecisionStepProcessor.ApplyStep`.
+  `DecisionStepProcessor.ApplyStep`. A `Post` issued *by the worker thread itself*
+  (the `EffectRunner` posting `ClassifierVerdictIssued` from inside `ApplyStep`) never
+  enters the bounded queue: it goes to a worker-local follow-up queue that is drained,
+  ahead of the channel, right after the current item — the worker is the queue's only
+  consumer, so blocking on a full channel there would freeze the pipeline for the rest
+  of the run.
 - `DecisionStepProcessor.ApplyStep` (same thread, no locks): journal append (the only
   hard-throwing path; 3 consecutive failures escalate to quarantine) → effects run
   synchronously via `EffectRunner` → best-effort snapshot → advance `CurrentState` →

docs/agent/overview.md

@@ -109,7 +109,9 @@ telemetry directly:
 ```
 Collector callback
   → SignalAdapter (dual emission: decision signal + InformationalEvent)
-    → SignalIngress.Post()            (bounded queue 256, back-pressure blocks producer)
+    → SignalIngress.Post()            (bounded queue 256, back-pressure blocks producer;
+                                       posts from the worker thread itself bypass the
+                                       queue via a worker-local follow-up queue)
       → single worker thread:
           assign ordinals → SignalLog.Append (durable)   ← source of truth
           → DecisionEngine.Reduce → apply step/effects

docs/agent/wifi-ssid-location-gate.md

@@ -0,0 +1,185 @@
+---
+type: Concept
+title: WiFi SSID and the Windows 24H2 Location Gate
+description: Why wifi_signal_info silently disappeared on Windows 11 24H2+ devices, why the netsh fallback could never fix it, and the tiered reader that restores the SSID from the SYSTEM context.
+resource: src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/WifiInfoProvider.cs
+tags:
+  - agent
+  - interop
+  - wifi
+  - telemetry
+timestamp: 2026-08-26T14:05:00+02:00
+---
+
+# Summary
+
+The agent reports the enrollment WiFi as a `wifi_signal_info` event (SSID, signal, PHY, channel).
+On Windows 11 24H2 and later the event went missing on a large share of devices — no error, no
+partial payload, simply no event. The cause is a Windows privacy change, not a bug in the reader:
+**`WlanQueryInterface` with `wlan_intf_opcode_current_connection` is gated behind precise-location
+consent**, and the agent runs as SYSTEM in session 0 where that consent usually does not exist.
+
+The fix is a tiered reader ([WifiInfoProvider](../../src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/WifiInfoProvider.cs))
+whose middle tier uses the one SSID API Microsoft left ungated.
+
+# The Gate
+
+Microsoft restricted the Win32 WLAN APIs that expose BSSIDs, because nearby-BSSID lists are a
+precise-location oracle. Without consent these return `ERROR_ACCESS_DENIED` (5):
+
+* `WlanGetAvailableNetworkList`
+* `WlanGetNetworkBssList`
+* `WlanScan`
+* **`WlanQueryInterface` when `OpCode` is `wlan_intf_opcode_current_connection`** — the only opcode
+  the agent needs, and the one that carries SSID, signal quality, PHY type.
+
+Two properties of the gate decide the agent's fate:
+
+1. **The consent prompt only appears for a process running in the user's context and outside
+   `C:\Windows\System32`.** The agent is neither during ESP: it is SYSTEM, in session 0, before any
+   user has seen the OOBE privacy page. It is therefore denied *silently* — no prompt, no event
+   log, nothing that surfaces without asking the API for its return code.
+2. **Consent resolves per user hive, with the device-level setting as the floor.** An interactive
+   user typically has
+   `HKCU\...\CapabilityAccessManager\ConsentStore\location\NonPackaged\Value = Allow`
+   ("Let desktop apps access your location"). The SYSTEM account (`HKU\S-1-5-18`) normally has
+   **nothing** set there and falls back to
+   `HKLM\...\ConsentStore\location\Value`. Where that device-level value is `Deny`, SYSTEM is
+   denied even though the logged-on user on the very same machine reads the SSID fine.
+
+That asymmetry is why the failure looks random from the outside: it tracks the **image's
+device-level location setting**, which varies per fleet, not per hardware, driver, or language.
+
+# Why netsh Was Never the Answer
+
+`NetshWifiFallback` was added in 2026-07 on the theory that inbox `netsh` still reported the
+connection where the WLAN API did not, and it was later extended with localized label variants for
+every enrollment-geography language. Field data says otherwise: **`netsh wlan` hangs off the same
+location gate** ("Network shell commands need location permission to access WLAN information"), so
+it fails in lockstep with tier 1 rather than covering for it. In the reported session the agent
+build already contained the netsh fallback and still produced no event.
+
+Consequence for future work: **adding more netsh language labels cannot fix a missing SSID.** Every
+`wifi_signal_info` event that does exist carries a fully populated SSID — the failure is binary at
+the reader level, never a half-parsed or mis-decoded payload. A missing SSID is an access problem,
+not a parsing problem.
+
+# The Tiered Reader
+
+`WifiInfoProvider.TryRead` owns the order so the two collectors (`DeviceInfoCollector`,
+`NetworkChangeDetector`) cannot drift apart. First non-null wins:
+
+| # | Reader | Yields | Location-gated |
+|---|---|---|---|
+| 1 | `WifiInfoReader` (native `wlanapi.dll`) | SSID, signal %, PHY, channel | yes |
+| 2 | `WinRtWifiSsidReader` (WinRT `GetConnectedSsid`) | SSID only | **no** |
+| 3 | `NetshWifiFallback` (process spawn, localized parse) | SSID, signal %, radio type, channel | yes |
+
+Tier 2 is Microsoft's own documented replacement for this exact scenario:
+`Windows.Networking.Connectivity.WlanConnectionProfileDetails.GetConnectedSsid()`. It is not part of
+the BSSID-bearing surface, so it needs no consent, and it has existed since Windows 10 1507.
+
+It is bound through the CLR's built-in WinRT projection with
+`Type.GetType("…, ContentType=WindowsRuntime")` — no NuGet package, no winmd reference, no csproj
+change — the same mechanism [OobeStateReader](../../src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/OobeStateReader.cs)
+already uses from the SYSTEM service context. Every step degrades to null rather than throwing,
+because the caller runs fire-and-forget inside `Task.Run`.
+
+# Telling the Operator
+
+A missing signal reading is indistinguishable from a bug unless the payload says why, and the
+device-level location setting is not something an admin would think to check. When tier 2 wins
+*and* the native tier reported `rc=5`, the `wifi_signal_info` payload therefore carries
+
+```
+wifiDataLimitedReason = "location_services_off"
+```
+
+and the event message gains `- signal unavailable, Location services off`, so the reason is visible
+in the timeline itself. The portal's WiFi card (`DeviceDetailsCard`) matches that literal and
+renders the explanation plus the Intune setting that fixes it. The value is a published contract —
+agent, portal and the MCP device-property catalog all match the same string.
+
+The claim is only made on observed evidence: any other native failure (no WLAN service, no
+connected interface) leaves the field null rather than blaming a privacy setting we did not
+measure. `WifiInfoProvider.IsLocationGateDenied` is the single predicate, pinned by tests at its
+boundaries (`rc=5` yes; `rc=50`, `rc=5023`, `rc=1062` no).
+
+The network timeline reads the same field. It needs no payload of its own: `buildSegments`
+already merges every `wifi_signal_info` into the WiFi segment covering its timestamp, so the
+reason rides in with the sample. A segment that never got a sample (a mid-session reconnect emits
+no `wifi_signal_info`) inherits it — the gate is a device-level setting and cannot flip during an
+enrollment — while a segment that *did* get a real reading is never overwritten. The segment
+tooltip then reads `Signal: unavailable - Location services off on this device` where the
+percentage would be, and the "Avg WiFi signal" stat says `n/a (Location services off)` instead of
+disappearing.
+
+`network_state_change` deliberately does NOT carry the reason: that event has never carried
+`signalPercent` or `radioType` at all (`NetworkChangeDetector` collects them into its snapshot for
+change detection but only `before_/after_wifiSsid` reaches the payload), so there is no absent
+field there for a reason to explain. Adding it would ship a field nothing reads. The SSID it does
+carry is unaffected by the gate.
+
+Fleet-wide the same field is queryable through
+`search_sessions(deviceProperties: { "wifi_signal_info.wifiDataLimitedReason": "location_services_off" })`,
+which sizes how much of a fleet is affected before anyone changes a policy.
+
+Tier 2 returns the SSID alone. Signal quality, PHY type and channel have no ungated source; they
+stay null when the native tier is denied. That is deliberate — deriving a percentage from
+`ConnectionProfile.GetSignalBars()` (0–5) would fabricate precision the API does not have.
+
+# Diagnostics
+
+The step-level native return codes were already collected, but they were logged with
+`_logger.Debug` — and the agent's default log level is `Info`, so the diagnostic built to explain
+this failure never reached a single field log. Both collectors now log at **Warning** when all tiers
+fail, which they only reach when the active NIC really is WiFi. A native `rc=5` is spelled out as
+`ERROR_ACCESS_DENIED` with the location-gate explanation, so the log line diagnoses itself:
+
+```
+EnrollmentTracker: no wifi_signal_info — no WiFi info from any reader — native: [<guid>]
+query(current_connection) rc=5; ; WinRT: no SSID; netsh: no parsable output. rc=5 is
+ERROR_ACCESS_DENIED — Windows 11 24H2+ gates the current-connection opcode (and netsh wlan)
+behind precise-location consent, which is off in this image; enable Location services to
+restore signal/PHY/channel.
+```
+
+# Evidence
+
+Session `7305e0ad` (HP EliteBook X Flip G1i, build 26200.9168, agent 2.0.1407, reported as
+`WIFI SSID fehlt`): `network_interface_info` shows the active NIC as `Intel(R) Wi-Fi 7 BE201`,
+`Wireless80211`, `connectionType=WiFi`, so the `isWifi` gate passed and collection ran — yet zero
+`wifi_signal_info` events across 214 events and 22 minutes, with the netsh fallback already shipped
+in that build.
+
+Fleet correlation over WiFi sessions from 2026-08-01 (n=276), share with a `wifi_signal_info` event:
+
+| OS build | WiFi sessions | with SSID |
+|---|---|---|
+| 22631 (23H2, pre-gate) | 3 | 100% |
+| 26100 (24H2) | 178 | 21% |
+| 26200 (25H2) | 95 | 45% |
+
+Within a single model the outcome splits by fleet, not by hardware — ThinkPad T14 Gen 6: 7/91;
+ThinkPad E14 Gen 7: 9/9 — which is what a per-image privacy setting looks like.
+
+Local verification (build 26220.9022): `HKLM\…\ConsentStore\location = Deny` while
+`HKCU\…\ConsentStore\location\NonPackaged = Allow`; the interactive user reads the SSID through
+both the native API and netsh, `HKU\S-1-5-18` has no consent value at all, and the WinRT chain
+resolves and returns the SSID under net48.
+
+# Operator Guidance
+
+A device that reports no SSID is not misconfigured for enrollment — only the telemetry field is
+missing. To get the full payload (signal, PHY, channel) back, the **device-level** location setting
+must be on: *Settings → Privacy & security → Location → Location services*, or via Intune
+(`Privacy/LetAppsAccessLocation`). Without it the SSID still arrives via tier 2.
+
+# Citations
+
+* [Changes to API behavior for Wi-Fi access and location](https://learn.microsoft.com/en-us/windows/win32/nativewifi/wi-fi-access-location-changes)
+* [WlanConnectionProfileDetails.GetConnectedSsid](https://learn.microsoft.com/en-us/uwp/api/windows.networking.connectivity.wlanconnectionprofiledetails.getconnectedssid)
+* [WifiInfoProvider.cs](../../src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/WifiInfoProvider.cs)
+* [WinRtWifiSsidReader.cs](../../src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/WinRtWifiSsidReader.cs)
+* [WifiInfoReader.cs](../../src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/WifiInfoReader.cs)
+* [NetshWifiFallback.cs](../../src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/NetshWifiFallback.cs)

docs/backend/admin-identity-binding.md

@@ -0,0 +1,165 @@
+---
+type: Concept
+title: Admin Identity Binding — tid + oid behind every cross-tenant-role UPN
+description: Why a GlobalAdmins or DelegatedAdmins row keyed on a UPN string must never confer access by itself in an API that accepts tokens from every Entra tenant, the AdminIdentityBindings table that pins each such UPN to its immutable home tenant id and object id, the fail-closed resolution order in both role services, the first-sign-in object-id pin, and the explicit rebind surface.
+resource: src/Backend/AutopilotMonitor.Functions/Services/AdminIdentityBindingService.cs
+tags:
+  - backend
+  - security
+  - authorization
+  - multi-tenant
+  - global-admin
+  - delegated-admin
+timestamp: 2026-08-29T00:00:00+02:00
+---
+
+# Problem
+
+The API is a multi-tenant Entra application on purpose: `AuthenticationMiddleware` accepts a token from
+any tenant (issuer prefix `login.microsoftonline.com/` or `sts.windows.net/`), and signature, audience,
+lifetime and algorithm are validated strictly. Tenant-member roles (`TenantAdmins`) are keyed on
+`(tid, upn)` and therefore bound to the verified tenant.
+
+The two cross-tenant tiers were not. `GlobalAdmins` (GlobalAdmin / GlobalReader) and the delegated MSP
+tier (`DelegatedAdmins` + `TenantGroupAssignments`) resolved their role from the **UPN string alone**
+(`upn`, falling back to `preferred_username`). Both claims are mutable and reusable across tenants:
+
+* **Domain re-registration**: if the domain behind a platform admin's UPN lapses or moves, whoever
+  verifies it in a fresh tenant can mint the identical UPN; the token is genuine, only `tid` differs.
+* **UPN recycling**: a User Administrator in the home tenant can re-assign the UPN to another account;
+  same `tid`, different `oid`.
+* **MSP variant**: the delegated tier was gated only on the caller's home tenant being Pro — which any
+  tenant can self-provision via the trial endpoint.
+
+Any of these yielded full platform scope: raw table dumps including `TenantConfiguration` secrets,
+tenant offboarding, GA management. Microsoft's own guidance (post-nOAuth) is explicit: authorization
+data must be keyed on the immutable `tid` + `oid` pair, never on `upn` / `preferred_username`.
+
+# Mechanism
+
+## One binding per UPN
+
+`AdminIdentityBindings` (PK `Bindings`, RK = lowercase UPN) holds, for every UPN that carries a
+cross-tenant role, the identity that may use it:
+
+| Column | Meaning |
+| --- | --- |
+| `TenantId` | The admin's **home** Entra tenant — must equal the JWT `tid`. Mandatory at grant time. |
+| `ObjectId` | The admin's Entra object id — must equal the JWT `oid`. Empty until pinned. |
+| `BoundBy`, `BoundDate` | Operator provenance. |
+| `ObjectIdPinnedDate` | When the object id was fixed (grant time, or the first matching sign-in). |
+
+A single table rather than columns on three role tables: a UPN string belongs to exactly one identity
+at a time, a person may hold a GlobalAdmins row *and* delegated assignments, and the role rows stay
+what they are — grants. The binding says whose grants they are.
+
+## Resolution order (both role services)
+
+`AdminIdentity` is the record `(Upn, TenantId, ObjectId)` built from a validated principal; it is
+`null` when any of the three claims is missing (app-only tokens, foreign IdP shapes). Both
+`GlobalAdminService.GetGlobalRoleAsync(AdminIdentity?)` and
+`DelegatedAdminService.GetScopeAsync(AdminIdentity?)` follow the same order:
+
+1. `null` identity → no role, no storage read.
+2. Resolve the **row** by UPN (cached 30 s, unchanged from before).
+3. No row / empty scope → return; the binding is not even read. Ordinary tenant users cost one cached
+   read and never produce a binding log line.
+4. `AdminIdentityBindingService.IsBoundAsync(identity)` → false ⇒ no role / empty scope.
+5. Delegated only: the Pro home-tenant entitlement gate, **after** the binding check — an unbound caller
+   never triggers an edition lookup.
+
+`IsBoundAsync` is the single choke-point: no binding ⇒ false; `TenantId` mismatch ⇒ false (checked
+before anything else, so a foreign-tenant token can never claim the pin below); pinned `ObjectId`
+mismatch ⇒ false; unpinned binding + matching tenant ⇒ **pin** the caller's `oid` and verify against
+what was actually stored afterwards. Every false outcome is logged at Warning with its reason
+(`[IdentityBinding] TENANT MISMATCH …` / `OBJECT-ID MISMATCH …` / `holds no identity binding`), the
+one level the worker forwards to Application Insights; matches are silent. Pins are logged at Warning
+once — they are one-off, operator-relevant events.
+
+The pin is a conditional update in the repository (`TryPinIdentityObjectIdAsync`: only onto an unpinned
+row homed in the caller's tenant, ETag-guarded; a 412 re-reads and the caller compares against the
+winner). Two accounts racing the first sign-in inside the home tenant therefore leave exactly one bound.
+
+Row lookups stay cached by UPN; the binding has its own 30 s cache keyed by UPN and is invalidated on
+pin, rebind and removal. A rebind on one scaled-out instance converges on the others within seconds.
+
+## Grants bind first — and resolve the identity themselves
+
+Granting is "type the UPN". The three grant endpoints (`POST auth/global-admins`,
+`POST global/delegated-admins`, `POST global/tenant-groups/{id}/assignees`) accept `homeTenantId` /
+`objectId` only as optional overrides; normally `AdminIdentityResolver` supplies them:
+
+1. **Sign-in history** (`UserActivity`, filtered on the UPN): the person has signed in before ⇒ tid + oid
+   are known, both from validated tokens. The most recent sign-in wins for the oid. A UPN seen under
+   **more than one tenant** is never auto-resolved — that is the attack shape the binding exists for.
+2. **UPN domain → onboarded tenant** (`TenantConfiguration.DomainName`, exactly one match): tid only; the
+   oid is pinned on the first sign-in.
+3. Neither ⇒ **422 `HomeTenantUnresolved`**; the portal then shows a home-tenant picker (onboarded
+   tenants) and retries with `homeTenantId`. This is the only manual step, and only for a UPN whose
+   domain the platform has never seen.
+
+`AddGlobalAdminAsync`, `DelegatedAdminService.UpsertAsync` and `AssignGroupAsync` then take the resolved
+`homeTenantId` / `objectId` and call `EnsureBoundAsync` **before** writing the role row. `EnsureBoundAsync` creates the binding, keeps a compatible one (same tenant; the
+supplied object id equals the pin or upgrades an unpinned one), and throws
+`IdentityBindingConflictException` for a different tenant or a different pinned object id — the
+functions map that to **409**. A grant can therefore never silently re-home a UPN.
+
+Why the object id may be unknown: a person who has never signed in has no history to resolve from, and
+the operator granting an external MSP admin has no directory access to the partner tenant. The first
+sign-in from the bound tenant pins it; from then on a recycled UPN in the same tenant is refused.
+
+## Explicit rebind surface
+
+| Route | Policy | Purpose |
+| --- | --- | --- |
+| `GET global/identity-bindings` | GlobalReadOrAdmin | Audit which tenant / object id each grant is usable from. |
+| `PUT global/identity-bindings/{upn}` | GlobalAdminOnly | Replace the binding: move a UPN to another tenant, or re-pin after a legitimate account re-creation (omit `objectId` to clear the pin). |
+| `DELETE global/identity-bindings/{upn}` | GlobalAdminOnly | Make every role row of the UPN inert without touching the rows. Self-removal is refused. |
+
+Both mutations are audited under the binding's home tenant (`AdminIdentityBinding` entity, previous
+values in the details) and logged at Warning. The portal surfaces this in **Tenant Management → Edit
+Tenant Configuration → Identity bindings** (collapsed): the bindings homed in that tenant, with inline
+edit (re-home / re-pin; empty object id ⇒ re-pinned on the next sign-in) and remove. The grant forms
+themselves carry no identity fields — the binding is a background property of the grant.
+
+## Lifecycle and secondary effects
+
+* `AdminIdentityBindings` is in `TableNames.All`, in `CriticalBackupTables.All` and in
+  `AuthTablesFullRestoreForbidden` (single-row restore only, like the other auth tables).
+* Tenant offboarding wipes bindings whose `TenantId` is the offboarded tenant (property-only bucket):
+  once a home tenant is gone, its admins' grants become inert.
+* `RequestContext.ObjectId` carries the JWT `oid`; `AdminIdentity.FromRequestContext` serves the
+  handlers that resolve roles outside the middleware (SignalR group join/leave, health checks).
+* The throttle identity (`GetCallerId`) now prefers `oid` over the UPN, so two accounts in different
+  tenants that share a UPN string no longer share a rate-limit bucket. Audit and presence rows keep the
+  UPN as their display key; they already carry the tenant id.
+* Legacy role rows without a binding are **inert, not grandfathered**. Rolling this out therefore means
+  seeding the binding rows for the existing admin UPNs (their `tid` and `oid` are recorded per login in
+  `UserActivity`) *before* the backend deploy — an unseeded platform admin locks themselves out of every
+  GlobalAdminOnly route, including the rebind surface.
+
+# Examples
+
+A GlobalAdmin row for `admin@vendor.example` bound to tenant `1111…` with object id `aaaa…`:
+
+| Token | Result |
+| --- | --- |
+| `tid=1111… oid=aaaa… upn=admin@vendor.example` | GlobalAdmin |
+| `tid=2222… oid=aaaa… upn=admin@vendor.example` | no role — `TENANT MISMATCH` warning |
+| `tid=1111… oid=bbbb… upn=admin@vendor.example` | no role — `OBJECT-ID MISMATCH` warning |
+| `tid=1111… upn=admin@vendor.example` (no `oid`) | no role — identity incomplete |
+
+Same row, binding without an object id: the first `tid=1111…` sign-in pins its `oid` and is admitted; a
+`tid=2222…` sign-in before that is refused **and does not pin**.
+
+# Citations
+
+* `src/Backend/AutopilotMonitor.Functions/Security/AdminIdentity.cs` — the identity record and its factories.
+* `src/Backend/AutopilotMonitor.Functions/Services/AdminIdentityBindingService.cs` — verdict, pin, grant-time binding, rebind; the table entity.
+* `src/Backend/AutopilotMonitor.Functions/Services/AdminIdentityResolver.cs` — sign-in-history / UPN-domain resolution at grant time (`AdminIdentityResolverTests`).
+* `src/Web/autopilot-monitor-web/app/admin/components/IdentityBindingsSection.tsx` — the per-tenant inspect/correct panel.
+* `src/Backend/AutopilotMonitor.Functions/Services/GlobalAdminService.cs`, `DelegatedAdminService.cs` — resolution order.
+* `src/Backend/AutopilotMonitor.Functions/DataAccess/TableStorage/TableAdminRepository.cs` — `TryPinIdentityObjectIdAsync` and the binding CRUD.
+* `src/Backend/AutopilotMonitor.Functions/Functions/Admin/IdentityBindingManagementFunction.cs` — the rebind surface and the shared `IdentityBindingRequest.Validate`.
+* `src/Backend/AutopilotMonitor.Functions.Tests/AdminIdentityBindingServiceTests.cs`, `AdminIdentityBindingAuthorizationTests.cs` — verdict matrix, race semantics, and the middleware-level denials for foreign-tenant and recycled-UPN tokens.
+* [Client-Certificate Tenant Binding](client-cert-tenant-binding.md) — the same "chain-valid is not tenant-bound" argument on the device side.

docs/backend/client-cert-tenant-binding.md

@@ -10,7 +10,7 @@ tags:
   - certificates
   - intune
   - multi-tenant
-timestamp: 2026-08-24T00:00:00+02:00
+timestamp: 2026-08-29T00:00:00+02:00
 ---
 
 # Problem
@@ -77,7 +77,7 @@ Enforcing immediately would be reckless: any device population whose certificate
 extension, or whose CA behaves differently (sovereign clouds), would be locked out at once. The
 rollout therefore has staged consequences.
 
-**Stage 1 — shadow (current).** `SecurityValidator.ObserveCertTenantBinding` evaluates the binding
+**Stage 1 — shadow (completed, kept as the measurement that justified stage 2).** `SecurityValidator.ObserveCertTenantBinding` evaluates the binding
 after certificate validation and logs the outcome. It returns `void`, changes no state, and swallows
 its own exceptions, so it cannot fail a request that would otherwise be accepted. The pure comparison
 lives in `CertTenantBinding.Evaluate`; the outcome codes (`Match`, `Mismatch`, `ExtensionMissing`,
@@ -102,14 +102,68 @@ is disabled), so a `Match` trace is dead code that silently costs the denominato
 deployment of this feature made exactly that mistake: it emitted zero rows across 32k requests,
 which is indistinguishable from the code never running.
 
-**Stage 2 — enforce.** Once telemetry shows the `ExtensionMissing` rate is negligible, `Mismatch`
-becomes a rejection. The decision that still has to be made is the policy for certificates without
-the extension: skip with a warning, or reject. Grep marker for every stage-2 site:
-`CERT-TENANT-BINDING-SHADOW`.
+**Stage 2 — enforced since 2026-08-25.** `Mismatch` returns 403 and is recorded through the shared
+`LogRequestRejection` path (`stage=certtenant`) so it lands in the same KQL raster as every other
+rejection reason. The switch was made against measured data: 35,684 requests across 32 tenants,
+every one a `Match`, with the Warning channel independently verified to be carrying other traffic so
+the zero could not be a telemetry artefact.
+
+The rule lives in one place, `CertTenantBinding.Rejects`, and only `Mismatch` blocks. Everything
+else means "cannot tell" and is deliberately tolerated:
+
+* `ExtensionMissing` — the sample only covers devices active in the measurement window, so older
+  certificates or a sovereign-cloud CA could still lack the extension. Rejecting on absence would
+  lock those devices out for something they cannot control. **This is the one to tighten later**,
+  once the `ExtensionMissing` rate is provably zero across a wider window; a test pins the current
+  tolerance so removing it has to be a deliberate decision rather than a drive-by edit.
+* `Unparseable` — a decoder or encoding surprise is our problem, not the device's.
+* `RequestTenantNotAGuid` — nothing to compare against, and such a request fails the tenant lookup
+  in §0 long before reaching this point.
+
+The evaluation fails open on its own exception: this gate exists to stop a cross-tenant certificate,
+and a defect on our side is not evidence of one. The 403 body deliberately does not echo which
+tenant the certificate belongs to — that pair is in the rejection log, not in the response.
+
+Grep marker for every site involved: `CERT-TENANT-BINDING`.
 
 The bootstrap-token path (`X-Bootstrap-Token`) bypasses certificate validation by design and is
 unaffected by either stage.
 
+# Certificate transport and proof of possession
+
+Every stage above validates certificate *content*: chain, validity window, EKU, tenant extension.
+None of them proves the caller holds the private key — a certificate is public material (sent in
+clear in a TLS 1.2 client-auth handshake, readable from the machine store by any local user, present
+on resold hardware). Proof of possession comes from the TLS handshake alone: the platform runs
+`clientCertMode=Required` on every path not listed in its `clientCertExclusionPaths`, forwards the
+handshake certificate as `X-ARR-ClientCert`, and **strips any inbound copy of that header — on
+excluded paths too** (verified 2026-08-29 with a spoofed header against `/api/bootstrap/config`:
+the validator saw "No certificate provided"). So `X-ARR-ClientCert` is trustworthy exactly because
+the caller cannot write it.
+
+Two consequences shape `SecurityValidator`:
+
+* **No other certificate header is ever read.** A former local-dev fallback (`X-Client-Certificate`)
+  accepted certificate bytes from a client-writable header, which decouples the certificate from
+  key possession: anyone holding a device's public certificate would authenticate as that device.
+  Removed 2026-08-29. Local development sets `X-ARR-ClientCert` directly — Core Tools does not strip
+  it.
+* **Bootstrap routes are token-only, fail-closed.** `/api/bootstrap/*` is in the platform's
+  exclusion list so cert-less OOBE agents can reach it — which also means nothing on those paths
+  proves a handshake happened. The token is therefore the sole credential there:
+  `SecurityValidator.IsBootstrapRoute` (path prefix, mirroring the exclusion entry so no function
+  can forget to opt in) rejects a missing or **empty** `X-Bootstrap-Token`, and a missing
+  `BootstrapSessionService`, with 401 before the certificate stage can run. The live gap this
+  closes: the function-level `Headers.Contains` gate accepted an empty header while the validator
+  treated it as "no token" and fell through to the certificate stage, where the fallback header
+  above was parsed. Bootstrap tokens are never accepted as a *replacement* for the certificate on
+  platform-enforced routes either — there the cert requirement is already satisfied by the
+  handshake before the request reaches code.
+
+The exclusion list is portal-only state (no IaC). Adding `/api/agent` to it, or moving a
+device-authenticated function under an excluded prefix, would silently reopen the header path;
+`BootstrapRouteFailClosedTests` pins the code half of this contract.
+
 **Stage 3 — device binding (Global-Admin-only preview).** Tenant binding proves the certificate was
 issued to this tenant; it does not prove the certificate belongs to a device the tenant still has.
 `IntuneDeviceBindingValidator` closes that by resolving the Intune managedDevice id from the

docs/backend/ime-msi-archive.md

@@ -0,0 +1,114 @@
+---
+type: Concept
+title: IME Installer Archive (version-verified, multi-host)
+description: How every fleet-observed Intune Management Extension build is archived as its MSI - the ime_agent_version sighting that queues the job, the candidate hosts, the ProductVersion check that keeps a wrong ring's build out of the version folder, the re-queue on later sightings, and the manual skill-side backfill.
+resource: src/Backend/AutopilotMonitor.Functions/Services/Ime/ImeMsiArchiver.cs
+tags:
+  - backend
+  - ime
+  - archive
+  - blob
+  - queue
+timestamp: 2026-08-29T17:30:00+02:00
+---
+
+# IME Installer Archive
+
+The platform keeps every Intune Management Extension build it has ever seen in the fleet
+as the original installer, so any IME version can be decompiled and diffed later
+(`ime-decompiles` repository, `/ime-decompile` skill) even after Microsoft's CDN has moved
+on. Two stores:
+
+| Store | Content | Written by |
+| --- | --- | --- |
+| Blob container `ime-archive` (private, kept by design, not tenant-scoped) | `{version}/IntuneWindowsAgent.msi` (write-once) + `{version}/provenance.json` (derived, overwritable) | `ImeMsiArchiver` via the `ime-msi-archive` queue; `/ime-decompile` skill as manual backfill |
+| Table `ImeVersionHistory` (partition `Global`, RowKey = version) | first/last seen, session count, `MsiArchiveStatus`, `MsiArchiveUpdatedAt`, `MsiArchiveBlobPath`, `MsiSha256`, `MsiBytes`, `MsiSourceUrl` | `RecordImeVersionAsync` (sighting), `UpdateImeVersionArchiveInfoAsync` (archive outcome / queued stamp) |
+
+# Schema
+
+## Sighting → job
+
+`EventIngestProcessor` looks at the batch's `ime_agent_version` event (`agentVersion`, plus
+the agent's CSP-registry enrichment `msiDownloadUrl` / `msiMatchedBy` when present).
+`RecordImeVersionAsync` returns an `ImeVersionSighting`:
+
+* `IsNew` — the insert succeeded: first fleet-wide sighting → ops event + enqueue.
+* otherwise the row's `MsiArchiveStatus` / `MsiArchiveUpdatedAt`, read in the same point
+  read that bumps `SessionCount` (no second table read).
+
+A known version is **re-queued** (`ImeMsiArchiver.ShouldRequeueOnSighting`) only when all
+of these hold: the event URL passes the allowlist **and** `msiMatchedBy == productVersion`
+(the CSP row's ProductVersion equals the observed version, so the URL is authoritative),
+the status is neither `Archived` nor `Failed:BadVersion`, and the last archive activity is
+older than 24 h (`RequeueBackoff`) or never happened. The ingest path then merges
+`MsiArchiveStatus = Queued` (stamping `MsiArchiveUpdatedAt`) before enqueueing, so the other
+sessions of that version see "in flight" and do not pile on. Worst case for a version no
+host serves any more: one walk over the hosts per day, not one per enrollment.
+
+## Candidate hosts and the version check
+
+Microsoft distributes IME from several versionless URLs that carry **different rollout
+rings at the same time**. Observed 2026-08-29: `imeswdb-afd-secondary` served 1.104.102.0,
+`imeswda-afd-primary` 1.105.101.0, `imeswda-afd-hotfix` 1.105.103.0. "A new version is by
+definition what the canonical URL serves right now" is therefore false, and the first
+version of the archiver filed a 1.104.102.0 package under `1.105.103.0/` (fixed by hand:
+blob overwritten, row merged).
+
+The archiver walks `BuildCandidateUrls(eventUrl)`: the allowlisted event URL first (HTTPS,
+host `*.manage.microsoft.com`, filename exactly `IntuneWindowsAgent.msi`), then
+`FallbackMsiUrls` = primary, secondary, hotfix — de-duplicated. For each candidate:
+
+1. Download with the admin size cap (Content-Length preflight + mid-stream cap) into a
+   delete-on-close temp file while SHA-256 hashing.
+2. Read the package's `ProductVersion` with `MsiProductVersionReader` — a pure managed OLE
+   compound-file reader (v3 512-byte and v4 4096-byte sectors, DIFAT/FAT/mini-FAT, MSI
+   stream-name decoding, `_StringPool`/`_StringData` incl. long strings and holes, the
+   column-major `Property` table with 2- or 3-byte string refs). It never throws; anything
+   unreadable is `null`. Needed because the Function host is Linux — no `msiexec`.
+3. `VersionsMatch(observed, productVersion)` (component-count tolerant: `1.105.103` ==
+   `1.105.103.0`). Mismatch or unreadable → log, record the attempt, next candidate.
+4. Match → write-once upload (If-None-Match:*), then `provenance.json` with
+   `productVersion`, the chosen `url`, `urlFromEvent`, hash/size and the full `candidates`
+   walk (`url`, `outcome` ∈ match / version-mismatch / too-large / download-failed /
+   timeout, `productVersion`).
+
+Outcome precedence when no candidate archived: any transient failure (download/timeout)
+→ `Failed:Download` / `Failed:Timeout`, retryable via the queue's visibility ladder (the
+down host might have had it); every candidate over the cap → `Failed:TooLarge`; otherwise
+`Failed:VersionMismatch` — **not** retryable by the queue (retrying in minutes changes
+nothing), left to the sighting re-queue above. Storage/unexpected errors stay
+`Failed:Error`, retryable. A 409 on the write-once upload means an earlier attempt
+archived the version: the provenance sidecar is healed from the archived bytes (hash,
+size, ProductVersion) if missing — this is also how a manual skill backfill turns a null
+row into `Archived` on the next authoritative sighting.
+
+## Manual path (skill)
+
+`/ime-decompile` downloads from the blob (`ime-blob.sh download`), and
+`fetch-ime-decompile.py` names the decompile folder after the **actual** FileVersion of
+the extracted binaries — so the decompile repo can never be poisoned, only the blob folder.
+When the blob's version mismatches, look for `msiDownloadUrl` in *other* sessions of the
+version (the first-seen session often lacks the enrichment) and fetch from that host.
+`ime-blob.sh upload … --overwrite` replaces a blob known to hold the wrong build; merge the
+row's `MsiSha256` / `MsiBytes` / `MsiSourceUrl` afterwards.
+
+# Examples
+
+* First sighting of 1.105.103.0 with no URL: primary → 1.105.101.0 (mismatch), secondary →
+  1.104.102.0 (mismatch), hotfix → 1.105.103.0 (match) → archived from hotfix, provenance
+  lists all three.
+* Hotfix host down during the walk, others mismatching → `Failed:Download`, queue retries.
+* Version 1.101.111.0 (predates the archiver, row status null): a session whose CSP row
+  matches by ProductVersion arrives → status `Queued`, job runs; if no host serves it any
+  more → `Failed:VersionMismatch`, next try no sooner than 24 h later.
+
+# Citations
+
+* `src/Backend/AutopilotMonitor.Functions/Services/Ime/ImeMsiArchiver.cs`
+* `src/Backend/AutopilotMonitor.Functions/Services/Ime/MsiProductVersionReader.cs`
+* `src/Backend/AutopilotMonitor.Functions/Services/Ime/ImeMsiArchiveQueueWorker.cs`
+* `src/Backend/AutopilotMonitor.Functions/Services/EventIngestProcessor.cs` (ime_agent_version block)
+* `src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.Sessions.cs` (`RecordImeVersionAsync`, `UpdateImeVersionArchiveInfoAsync`)
+* `src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/ImeMsiInstallSourceProbe.cs` (event enrichment)
+* `.claude/commands/scripts/ime-blob.sh`, `.claude/commands/scripts/fetch-ime-decompile.py`
+* Tests: `ImeMsiArchiverTests`, `MsiProductVersionReaderTests` (synthetic packages + local sweep over `ime-files/`)

docs/backend/session-owner-binding.md

@@ -0,0 +1,157 @@
+---
+type: Concept
+title: Session Owner Binding — Session-Level Authorization for Agent Writes
+description: Why tenant-level agent authentication (any device certificate, or a bootstrap token) was enough to rewrite every session in the tenant, how each Sessions row is now bound to the device identity that created it, the rule matrix that keeps every legitimate lifecycle working, the shadow-then-enforce rollout, and why enforcement needs the agent to rotate its session id rather than count an auth failure.
+resource: src/Backend/AutopilotMonitor.Functions/Security/SessionOwnershipPolicy.cs
+tags:
+  - backend
+  - security
+  - authorization
+  - sessions
+  - agent
+  - multi-tenant
+timestamp: 2026-08-29T00:00:00+02:00
+---
+
+# Problem
+
+Agent endpoints authenticate at **tenant** granularity: a chain-valid Intune MDM certificate whose
+tenant stamp matches the request (see [client-cert-tenant-binding.md](client-cert-tenant-binding.md)),
+or a bootstrap token minted for the tenant. They authorize writes at **session** granularity using a
+session id the caller supplies — `IngestTelemetryFunction` takes it from the `PartitionKey` of the
+first item, `RegisterSessionFunction` from the body, `ReportAgentErrorFunction` from the body. Until
+2026-08-29 nothing on the Sessions row recorded which device created it, so nothing could be compared.
+
+The consequence: one enrolled device — or anyone who saw a 6-character bootstrap short code — could,
+for every other session of the tenant, forge `enrollment_complete` / failure events (flipping the live
+status, firing webhooks and SLA logic), pollute the timeline, re-register the session with different
+device metadata (which also redirects the Progress-Portal serial-knowledge proof), and — worst — send a
+Signal-only batch that **fetches and clears the victim's pending ServerActions**, silently stealing
+admin commands such as diagnostics collection. Session ids are GUIDs, but they travel in portal URLs
+and tenant SignalR messages; they were never meant to be a capability.
+
+# Mechanism
+
+## Owner on the row
+
+`SessionOwner` (Shared) is stamped by the backend from the validated caller identity — never from
+agent input — and lives in six primary-only Sessions columns (`OwnerKind`, `OwnerThumbprint`,
+`OwnerDeviceId`, `OwnerBootstrapCode`, `OwnerSerial`, `OwnerBoundAt`). They are listed in
+`SessionIndexFieldManifest.PrimaryOnly`: never mirrored to `SessionsIndex`, never on `SessionSummary`,
+so no certificate identity travels to clients.
+
+| Auth path | Identity that binds | Proven by |
+|---|---|---|
+| Certificate | `OwnerThumbprint` + `OwnerDeviceId` (Intune device id from the certificate CN, lower-case GUID) | TLS handshake; the CN survives a certificate re-issue |
+| Bootstrap token | `OwnerBootstrapCode` + `OwnerSerial` | Token possession + the serial the caller announced (header, unverified) |
+
+`SecurityValidationResult.IntuneDeviceId` is new: the CN was already extracted for the Cloud PC
+validator, now it is surfaced on the result for every certificate-authenticated request.
+
+## Rule matrix
+
+`SessionOwnershipPolicy.Evaluate(existingRow, validation, now)` is pure. It returns an outcome, the
+owner to stamp (if any) and whether the caller's serial equals the row's serial.
+
+| Caller | Row owner | Outcome | Stamps | Would reject |
+|---|---|---|---|---|
+| any | no row | `Fresh` | caller | no |
+| any | no owner columns (legacy), serial equal | `ClaimLegacy` | caller | no |
+| any | no owner columns, serial differs | `LegacySerialMismatch` | — | **yes** |
+| any | — (validation carried neither thumbprint nor code) | `CallerUnidentified` | — | no |
+| Cert | Cert, same thumbprint | `Match` | — | no |
+| Cert | Cert, other thumbprint, same device id | `RebindCertRotation` | caller | no |
+| Cert | Cert, other thumbprint and device id | `MismatchCert` (+ `serialMatch`) | — | **yes** |
+| Cert | Bootstrap, same serial | `RebindBootstrapHandoff` | caller | no |
+| Cert | Bootstrap, other serial | `MismatchBootstrapOwned` | — | **yes** |
+| Bootstrap | Bootstrap, same code + serial | `Match` | — | no |
+| Bootstrap | Bootstrap, otherwise | `MismatchBootstrap` | — | **yes** |
+| Bootstrap | Cert | `DowngradeToBootstrap` | — | **yes** |
+
+The tolerated rows are the legitimate lifecycle: agent restart and reboot (same certificate),
+WhiteGlove Part 2 (same certificate), the install→runtime handoff where a bootstrap-registered session
+continues under the MDM certificate once it exists, a re-issued certificate of the same Intune device,
+and rows that predate the binding.
+
+`MismatchCert` with `serialMatch=true` is the one shape that is *not* an attack: an Intune
+re-enrollment **without a wipe**. `session.id` survives in `%ProgramData%\AutopilotMonitor`, but the
+device gets a new Intune device id and therefore a new certificate identity. Under enforcement this
+would be refused — which is why enforcement needs the agent-side rotation below.
+
+## Where it runs
+
+`SessionOwnerBindingObserver` is the single side-effect carrier; the three call sites hand it the
+row they already hold:
+
+* `RegisterSessionFunction.ProcessRegisterAsync` — the cascade-delete guard now returns the row
+  (`EnsureWritableAndGetRowAsync`); the decision's owner goes into `StoreSessionAsync(registration,
+  ownerToStamp)`, whose Replace preserves an existing owner when nothing new is stamped (including a
+  Merge-stamped owner that landed after the initial read — the CAS re-read selects the owner columns).
+  The bootstrap wrapper inherits this.
+* `IngestTelemetryFunction.Run` — evaluated against `guardSessionRow` (zero extra reads) before
+  `PersistItemsAsync`, so the Signal-only path that serves pending ServerActions is covered. Legacy
+  claims and rebinds are written with `UpdateSessionOwnerAsync` (Merge, fail-soft).
+* `ReportAgentErrorFunction` and its bootstrap wrapper — one point-read, observe only.
+
+## Shadow telemetry (stage 1)
+
+Same three carriers as the cert-tenant binding:
+
+* **Denominator** — `requests | extend o = tostring(customDimensions.SessionOwnerBinding) | where
+  isnotempty(o) | summarize count() by o` (request-row dimension via `RequestTelemetryMiddleware`;
+  worker `LogInformation` never reaches App Insights).
+* **Numerator** — `traces | where message startswith "AgentSessionOwnerBinding"` — one Warning per
+  non-Match/non-Fresh request with `outcome`, `wouldReject`, `callerKind`, `ownerKind`, `serialMatch`,
+  `endpoint`, `ver`.
+* **Operator signal** — ops event `SessionOwnerMismatch` (Security / Warning, dual-registered in the
+  admin alert-rule catalog) for would-reject outcomes, throttled to one per session+outcome per hour.
+  `serialMatch=true` counts re-enrollments without wipe; `serialMatch=false` is a foreign device.
+
+Nothing is refused in stage 1. `SessionOwnershipPolicy` deliberately has no `Rejects` member
+(pinned by `SessionOwnershipPolicyTests.Stage1_has_no_Rejects_rule`).
+
+## Enforcement contract (stage 2, not yet built)
+
+* Backend: `Rejects(outcome)` = the would-reject set; register/ingest/error answer 403 with
+  `RegisterSessionResponse.ErrorCode = Constants.AgentErrorCodes.SessionOwnerMismatch`
+  (`"session_owner_mismatch"`). The code and field already exist so the agent could ship first.
+* Agent (shipped dormant with this change): `BackendApiClient` reads `errorCode` off a JSON 401/403
+  body into `BackendAuthException.ErrorCode`; `SessionRegistrationHelper` reacts to exactly that code
+  by calling `rotateSession` once and re-registering immediately — **without** feeding
+  `AuthFailureTracker` (five consecutive 403s would otherwise soft-shutdown a perfectly authorized
+  agent). `BackendSessionRegistration.RotateSession` rotates `session.id` (keeping
+  `whiteglove.complete`), re-targets `agentConfig.SessionId` and the `EmergencyReporter`, and drops
+  `spool.jsonl` + `upload-cursor.json` because their lines carry the refused partition key. The
+  `agent_started` event then reports `sessionRotated=true` + `previousSessionId`.
+* Registration is the first session-scoped call of every agent start and everything after Phase 6
+  reads `agentConfig.SessionId` live, so a mismatch on ingest can only mean an agent older than the
+  rotation logic or a genuinely foreign caller.
+
+Switch on only after: the shadow distribution has run for weeks, every `wouldReject=true` is
+explained, and the fleet's `X-Agent-Version` is at or above the rotation-capable release. Then add
+`Rejects`, delete the stage-1 pin test, update the trust pages (isolation model) and bump their
+"Last reviewed" date.
+
+# Residual risk (accepted)
+
+* The serial is a caller-supplied header on both paths. A certificate holder who also knows a victim's
+  serial can still claim a **legacy** row, or a **bootstrap-owned** row during its handoff window.
+* One bootstrap token serves many devices; two devices on the same short code can still write into
+  each other's session until the certificate handoff closes it.
+* `SupersedeOrphanedPredecessorsAsync` is keyed on the announced serial and can still resolve foreign
+  open sessions to `Incomplete`. Follow-up: restrict to rows without owner or with the same
+  `OwnerSerial`, and require a minimum age.
+
+None of these are closable without a signature scheme over the request body, which is deliberately
+not built (it would duplicate the TLS proof).
+
+# Citations
+
+* `src/Backend/AutopilotMonitor.Functions/Security/SessionOwnershipPolicy.cs` — matrix, `WouldRejectUnderEnforcement`, row (de)serialization
+* `src/Backend/AutopilotMonitor.Functions/Services/SessionOwnerBindingObserver.cs` — carriers, throttle, stamping
+* `src/Shared/AutopilotMonitor.Shared/Models/Enrollment/SessionOwner.cs` — column names and kinds
+* `src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.Sessions.cs` — `StoreSessionAsync(…, ownerToStamp)`, `UpdateSessionOwnerAsync`
+* `src/Agent/AutopilotMonitor.Agent.V2.Core/Security/SessionRegistrationHelper.cs` — rotation branch
+* `src/Agent/AutopilotMonitor.Agent.V2/Runtime/BackendSessionRegistration.cs` — `RotateSession`
+* Tests: `SessionOwnershipPolicyTests`, `SessionOwnerBindingObserverTests`, `StoreSessionReregistrationPreserveTests`, agent `SessionRegistrationHelperTests`, `BackendSessionRegistrationTests`, `SessionIdPersistenceTests`, `BackendApiClientAuthClassificationTests`
+* Grep marker: `SESSION-OWNER-BINDING`

docs/backend/silent-session-classification.md

@@ -10,7 +10,7 @@ tags:
   - classification
   - whiteglove
   - self-deploying
-timestamp: 2026-08-23T18:00:00+02:00
+timestamp: 2026-08-27T20:00:00+02:00
 ---
 
 # Silent-Session Classification
@@ -30,7 +30,10 @@ so a session gets the same verdict regardless of which path noticed the silence
 subcategory counts (incl. the 30s fallback-confirmed messages), `HasExplicitFailure`,
 `HasEnrollmentComplete` vs. `HasTerminalComplete` (the Part-1 `whiteglove_complete`),
 `HasAgentEmergencyBreak`, `DesktopArrived`, `HelloResolved`, `HelloPolicyDisabled`,
-`SkipUserEsp`, RealmJoin detection/resolution. Session-row flags are passed alongside:
+`SkipUserEsp`, RealmJoin detection/resolution, `HasAppInstallFailure` (any
+`app_install_failed`), and `HasAgentMaxLifetimeTimeout` (either max-lifetime shape:
+`enrollment_failed`/`agent_timeout` or `agent_shutting_down`/`max_lifetime` — the agent is
+provably gone). Session-row flags are passed alongside:
 `IsPreProvisioned` + `ResumedAt` (WhiteGlove Part 2) and `IsSelfDeployingProfile`
 (registry-confirmed `CloudAssignedOobeConfig 0x20|0x40`, set at registration).
 
@@ -44,7 +47,9 @@ subcategory counts (incl. the 30s fallback-confirmed messages), `HasExplicitFail
 | 2 | Account Setup all-succeeded, or `enrollment_complete`, or `whiteglove_complete` on a **non-resumed** session | Succeeded |
 | 3 | `HasAgentEmergencyBreak` | Incomplete immediately (agent self-destructed, nothing can arrive) |
 | 4 | `DesktopArrived` + (Hello terminal, or Hello disabled + SkipUserEsp) | Succeeded (user provably finished) |
-| 5 | Device Setup done | AwaitingUser within grace, Incomplete past grace |
+| 5 | Device Setup done + within grace + **no** max-lifetime watchdog observed | AwaitingUser |
+| 5a | Device Setup done + past grace (or watchdog observed) + `DesktopArrived` + no `app_install_failed` | **Succeeded** — completed (assumed), `r5_assumed` |
+| 5b | Device Setup done, otherwise past grace (or watchdog observed) | Incomplete |
 | 6 | otherwise | Incomplete |
 
 Grace = `ResolveGraceHours(SessionGraceHours, AbsoluteMaxSessionHours)` (~51h default),
@@ -65,7 +70,12 @@ budget on a Wi-Fi link still associating), and rule 5 labeled finished kiosks
 Incomplete turned a working rollout into a red wall. Other self-deploying tenants completed
 normally in the same window, so this is a classification gap, not a profile-wide agent bug.
 Agent-side companion fix: `SessionRegistrationHelper` now waits up to 15s for a network link
-and retries 6× (~62s backoff) instead of 5× (~30s).
+and retries 6× (~62s backoff) instead of 5× (~30s). Measured 2026-08-27 (builds
+2.0.1428/1429, both carrying the fix): the reconcile share did not move, and the backend saw
+no registration attempt from any relaunch — no success, no 4xx, zero `register:superseded`
+in the tenant — so the relaunch never reaches the network at all (device powered off after
+ESP, or the relaunch never runs). The sweep reconcile is the permanent completion path for
+this profile, not a stopgap.
 
 ## Callers (all pass both gate inputs)
 
@@ -78,13 +88,33 @@ and retries 6× (~62s backoff) instead of 5× (~30s).
 | Agent stall probe (`session_stalled`) | `EventIngestProcessor.TryMapStallToWhiteGloveAwaitingUserAsync` | Only the WG gate (1b); a stall probe on a self-deploying device with Device Setup done means the agent is alive and something else blocks — stays Stalled. |
 | Admin retro-reconcile | `LegacyReclassificationService` | Modes `legacy_timeouts`, `pending_orphans`, `self_deploying_silent` (Incomplete/AwaitingUser/Stalled rows with the profile flag, heal-only to Succeeded, admin-marked rows skipped). `POST /api/maintenance/reclassify-legacy?mode=…&dryRun=false&tenantId=…&maxSessions=…`, dry-run by default. |
 
-## Known gap (decided, not built)
+## Why rule 5a exists (calibration read 2026-08-27)
+
+The verdict-calibration matrix showed r5-Incomplete devices re-enrolling at 2.6 % within
+7 days — the succeeded background (`agent:complete_soft` sits at 2.8 %), not the ~29 %
+failure level — consistently across tenants, and half the sampled sessions were healthy
+desktops with a clean app record whose agent died before the Hello terminal (some with the
+agent's own "AccountSetup treated as complete" synthesis as the literally last event). Past
+the full grace, "the user phase is still running" is no longer a possible explanation, so
+desktop + zero `app_install_failed` + no explicit failure now reconciles to Succeeded
+("completed (assumed)") instead of a red Incomplete. Sessions without a desktop (user never
+began sign-in: battery-drained, powered off, max-lifetime) and sessions with any failed app
+stay Incomplete — "completed" must not overclaim. Rule 4 remains the IMMEDIATE reconcile
+(desktop + Hello proof); 5a only fires where waiting is over. Desktop arrival alone is still
+rejected as a live completion signal.
+
+## Closed gap: max-lifetime AwaitingUser (2026-08-27)
 
 After max-lifetime the agent writes `enrollment-complete.marker` and self-destructs, so an
-AwaitingUser verdict from that path can never heal — it is a 51h countdown to Incomplete.
-The emergency-break path (rule 3) already terminalizes immediately; max-lifetime still goes
-through the grace window by design ("user simply absent"). Revisit if customers read
-AwaitingUser as "still possible".
+AwaitingUser verdict from that path could never heal — the calibration correction stream
+confirmed it: all five observed `maxlife:r5_awaiting` episodes expired to Incomplete
+unhealed, while live-agent `sweep:r5_awaiting` parks upgraded 7 of 26 to Succeeded. Rule 5
+therefore skips the grace once `HasAgentMaxLifetimeTimeout` is in the stream and decides the
+terminal fork (5a/5b) immediately; the max-lifetime ingest appends its trigger event to the
+read stream so the fact is never missed, and late straggler telemetry still heals a terminal
+verdict via `TryLateTelemetryReconcileAsync`. WhiteGlove rule 1b deliberately keeps its
+park — sealed/boxed devices do heal (the observed `maxlife:r1b_awaiting` episode resolved to
+Succeeded).
 
 # Examples
 

docs/backend/tenant-activation-welcome-mail.md

@@ -58,6 +58,24 @@ The Global-Admin resend endpoint (`POST /api/preview/send-welcome-email/{tenantI
 always sends (explicit intent) and consumes the marker best-effort so the automatic
 paths never duplicate afterwards.
 
+## Finding the tenant behind an address
+
+The provider's delivery log names only the recipient — never the tenant it belonged to. The
+reverse lookup is therefore part of the tenant console: its search matches `tenantId`,
+`domainName`, `ContactEmail` **and** the notification address. No other address is searchable
+(an admin UPN never receives platform mail and would only widen the PII surface of the list).
+
+The addresses live in a different table than the tenant configs the list is built from, so the
+console loads them as a map from `GET /api/preview/notification-emails` (GA + read-only Global
+Reader, `excludeDelegated`) — one cross-partition scan of `RowKey eq 'notification-email'`
+instead of a point read per tenant. Keys are lowercased on both sides of the join: the address
+rows are written from the JWT `tid` (lowercase) while a config PartitionKey's casing is not
+guaranteed. Stored addresses keep the casing the user typed, so matching is case-insensitive.
+
+The map is **best-effort** in the portal: it powers only the search-by-address, so a failed read
+degrades that one capability instead of taking the tenant list down. The addresses are not
+rendered in the list — they are a search key, and stay visible in the tenant editor.
+
 ## Mail transport
 
 Both transactional mails (welcome, post-offboarding farewell) go through the
@@ -118,3 +136,4 @@ properties `Html`, `UpdatedBy`, `UpdatedUtc`), cached 5 minutes, invalidated on
 * `src/Backend/AutopilotMonitor.Functions/Services/EmailTemplateService.cs` — override resolution, placeholder rendering, cache
 * `src/Backend/AutopilotMonitor.Functions/Functions/Admin/EmailTemplatesFunction.cs` — GA endpoints (read / override / reset / test send)
 * `src/Web/autopilot-monitor-web/app/admin/settings/sections/SectionEmailTemplates.tsx` — portal editor, preview frame, test send
+* `src/Web/autopilot-monitor-web/app/admin/components/tenantSearch.ts` — the console's match rules (searchable fields, quoted exact mode, lowercased join)

docs/backend/verdict-calibration.md

@@ -9,7 +9,7 @@ tags:
   - classifier
   - calibration
   - regression-radar
-timestamp: 2026-08-23T18:00:00+02:00
+timestamp: 2026-08-27T20:00:00+02:00
 ---
 
 # Verdict Calibration (classifier thermometer)
@@ -114,15 +114,18 @@ and is wiped with the tenant on offboarding.
 ## Drift radar — `VerdictCalibrationRadar`
 
 Same statistics as the [rule regression radar](rule-regression-radar.md) (7-day window vs the
-prior 28 days, ≥ 5 window hits, ≥ 20 window sessions, lift ≥ 2, `MetricsMath.
-RateIncreaseSeparated`), anchored on yesterday, over every partition with rows (each tenant
-and `global`):
+prior 28 days, ≥ 20 window sessions, lift ≥ 2, `MetricsMath.RateIncreaseSeparated`), with
+stricter floors since the first-month tuning (2026-08-27): **≥ 10 window hits** (verdict
+shares on single-digit counts are noise — a 3-hit episode survived as such), and a per-path
+share regression additionally needs **≥ 5 baseline hits** — a path with no established
+baseline is new (or renamed) vocabulary, not a regression. Anchored on yesterday, over every
+partition with rows (each tenant and `global`):
 
 | Kind | Signal | Re-arm |
 | --- | --- | --- |
-| `share_regression` | one **backend-decided** path's share of all sessions doubled (`sweep`/`maxlife`/`late`/`retro`/`rule`/`manual`/`ingest`; `agent:*` and `register:*` mirror customer workflow mix — first prod pass fired on `agent:whiteglove_pending` rollout weeks — and `legacy:*` is derived, all excluded) | share < 1.5× baseline, the path stops occurring, or the path is no longer eligible |
-| `silence_share_regression` | the `sweep:*` + `maxlife:*` share doubled — the backend had to decide more often because the agent went silent (a liveness signal, not a classifier one) | same |
-| `evidence_gap` | absolute: `r6` (pure fallthrough) decides ≥ 20 % of the window's classifier verdicts, ≥ 20 verdicts | < 15 % or < 20 verdicts |
+| `share_regression` | one **backend-decided** path's share of all sessions doubled (`sweep`/`maxlife`/`late`/`retro`/`rule`/`manual`/`ingest`; `agent:*` and `register:*` mirror customer workflow mix — first prod pass fired on `agent:whiteglove_pending` rollout weeks — and `legacy:*` is derived, all excluded per-path) | share < 1.5× baseline, the path stops occurring, the path is no longer eligible, or the current numbers fall below the fire floors |
+| `silence_share_regression` | the `sweep:*` + `maxlife:*` share doubled — the backend had to decide more often because the agent went silent (a liveness signal, not a classifier one). Rule-shaped `legacy:*` paths count into BOTH sums (window and baseline): they were the same backend decisions before the 2026-08-23 instrumentation, and without that continuity the group had a near-zero baseline by construction and fired a lift-124 rollout artifact | share < 1.5× baseline or hits stop |
+| `evidence_gap` | absolute: `r6` (pure fallthrough) decides ≥ 20 % of the window's classifier verdicts (stamped rule paths plus rule-shaped `legacy:*`, same continuity), ≥ 20 verdicts | < 15 % or < 20 verdicts |
 
 Episodes are tracker rows `verdictcalibration|{kind}|{path}|{status}` (register = `AddEntity`,
 409 = already burning, fail-closed; refresh carries `FirstNotifiedAt`; 30-day tracker
@@ -140,6 +143,15 @@ Kill switch `VerdictCalibrationRadarDisabled`.
   re-enrollment within 7 days after Succeeded 8.9 % (lab background), after Failed 24.3 %,
   after Incomplete 10.6 % — Incomplete behaves like Succeeded, so rules 5/6 are probably too
   cautious; the matrix now shows this per rule instead of per status.
+* **First real calibration read (2026-08-27, four days instrumented):** the per-rule and
+  per-tenant split resolved that hand analysis — `legacy:r5_incomplete` re-enrolled at 2.6 %
+  (the `agent:complete_soft` background), spread across tenants, while `legacy:r6`'s 29 %
+  was concentrated in one tenant that disciplinedly redoes failed enrollments (48.5 % there,
+  6.7 % elsewhere — so r6 stays untouched, it correctly flags that tenant). Consequences
+  shipped the same day: rule 5a "completed (assumed)" (see
+  [Silent-Session Classification](silent-session-classification.md)), the max-lifetime grace
+  skip, and the radar floors + legacy group continuity above — the first production month
+  had produced nine standing alerts, every one an instrumentation-rollout artifact.
 * **Correction stream:** a session swept to `sweep:r5_incomplete`, later completed by the
   agent → row `agent:complete` with `PriorVerdictPath = sweep:r5_incomplete`; the aggregate
   increments `OverriddenByLateCompletion` on the `sweep:r5_incomplete / Incomplete` bucket.

docs/backend/vulnerability-correlation-sources.md

@@ -0,0 +1,160 @@
+---
+type: Concept
+title: Vulnerability Correlation Sources (NVD, KEV, MSRC, EPSS)
+description: How the software inventory is turned into CVE findings - CPE mapping, the per-CPE NVD cache with its budget and TTLs, KEV/MSRC/EPSS enrichment, the throttle contract that keeps a refused NVD answer out of the cache, and the act/attend/track priority.
+resource: src/Backend/AutopilotMonitor.Functions/Services/Vulnerability/VulnerabilityCorrelationService.cs
+tags:
+  - backend
+  - vulnerability
+  - nvd
+  - epss
+  - kev
+  - msrc
+  - cache
+timestamp: 2026-08-29T18:00:00+02:00
+---
+
+# Vulnerability Correlation Sources
+
+The Software Inventory & Vulnerability Analyzer (tenant opt-in) ships the installed-software
+list with the session; the backend turns it into CVE findings entirely from cached public
+reference data. Four sources, all trustworthy primaries, no aggregators:
+
+| Source | What it contributes | Fetch shape | Cache |
+| --- | --- | --- | --- |
+| NVD 2.0 (NIST) | CVE records per product: CVSS v3.1 (v3.0 fallback) score, severity, **vector**, description, affected version ranges; CPE dictionary for auto-mapping | `cves/2.0?virtualMatchString={cpe}` per product, `cpes/2.0?keywordSearch=` for unmapped titles; optional API key (`AdminConfiguration.NvdApiKey`) | Azure Table `VulnerabilityCache`, one row per CPE (`cve_{cpe}` / `cache_result`), `CveDataJson` chunked; soft TTL 7 d (serve + background refresh), hard 14 d |
+| CISA KEV | "Exploited in the wild" flag, due date, required action, ransomware use | Whole catalog JSON | In-memory dictionary, 24 h, blob mirror `kev-catalog.json` |
+| MSRC | Microsoft-side confirmation: document id/title, release date, Microsoft severity / score / vector | CVRF v3.0 index of the last six Patch Tuesdays | In-memory index, blob mirror `msrc-index.json` |
+| FIRST EPSS | Probability (0..1) that the CVE is exploited within 30 days + percentile + scoring date | `api.first.org/data/v1/epss?cve=a,b,c` - 100 ids per request, unauthenticated | Stored **on the cached CVE** (no separate table): filled when a CPE row is (re)fetched, re-scored for every row by the nightly sync |
+
+Nothing about a tenant leaves the backend. The one outbound query that carries content is the
+EPSS lookup, and its payload is the list of public CVE ids held in the shared, tenant-agnostic
+CPE cache. Customer-facing wording: `autopilotmonitor-docs/trust/data-flows.md` and the
+terms page attribution block.
+
+# Schema
+
+## Cached CVE (`CachedCve`, serialised into `CveDataJson`)
+
+```
+CveId, CvssScore, CvssSeverity, CvssVector?, Description (<=500), PublishedDate,
+EpssScore?, EpssPercentile?, EpssDate?, AffectedVersions[] {Criteria, VersionStart/End Incl/Excl}
+```
+
+`JsonOptions` is `WhenWritingNull` + case-insensitive, so rows written before the vector / EPSS
+properties existed deserialise with those as `null`, and a row is never rewritten just to add
+nulls. `CveCacheBudget` bounds the row (24 months, or CVSS >= 7 within 60 months; max 100 CVEs
+per CPE, 50 ranges per CVE) - which is also why one CPE fill is exactly one EPSS request.
+
+`ProjectNvdResponse` is the single NVD -> `CachedCve` projection; the live fill and the nightly
+refresh both call it, so both write the same shape. `BuildCveCacheRow(cpe, cves, cachedAt)` is the
+single row builder; `cachedAt` is the **NVD** freshness stamp, an EPSS-only rewrite passes the
+existing value through so it does not look like a fresh NVD fetch to the 7-day TTL.
+
+## Per-finding output (report `findings[].vulnerabilities[]`)
+
+```
+cveId, cvssScore, cvssSeverity, cvssVector?, description, publishedDate, source ("NVD" | "NVD+MSRC"),
+isKev, kevDueDate, kevRequiredAction, knownRansomware,
+epssScore?, epssPercentile?, epssDate?,
+priority ("act" | "attend" | "track"),
+msrc* (when MSRC confirmed), versionMatchConfidence ("low" on wildcard CPE matches)
+```
+
+Finding level: `riskLevel` (unchanged CVSS+KEV bands), `priority` (highest band), `maxEpssScore?`.
+`scan_summary` additionally carries `act_cves` / `attend_cves`. `MergeReports` (Part 1 + Part 2)
+recomputes all of these. The `CveIndex` row (one per tenant/CVE/session) carries `EpssScore`
+(max over occurrences, absent when unscored) and `Priority` (highest), which the fleet summary
+(`TopCve.epssScore` / `priority`) reads.
+
+## Priority (`CvePriority.Compute`)
+
+* `act` - in CISA KEV.
+* `attend` - EPSS >= 0.1 **or** CVSS >= 9.0.
+* `track` - everything else.
+
+Three visible rules instead of a weighted composite: severity (`riskLevel`) keeps saying how bad,
+priority says how soon. A CVE without an EPSS score is "unknown likelihood" - it can still reach
+`attend` via CVSS, never via a defaulted 0. The thresholds are constants; changing them is a
+product decision, not a tuning knob.
+
+# Throttle contract (NVD)
+
+The typed `HttpClient` runs under the `ExternalDataApi` Polly policy: 429/5xx/timeouts are retried
+three times (1/2/4 s + jitter) with a circuit breaker. A 429 that reaches `NvdApiClient` therefore
+means NVD is refusing us for real. Two things then happen, and one deliberately does not:
+
+1. `NvdFetchResult<T>` reports `Succeeded = false`, `Throttled = true`. `Data` is an empty object
+   so enumerating callers keep working, but **nothing that persists may treat it as an answer**:
+   the CPE cache fill returns null and writes no row; the negative auto-resolve cache is not
+   touched; the admin auto-resolve reports `nvd_throttled`. Before this contract an empty response
+   was cached as "0 CVEs" for seven days - a product NVD happened to throttle disappeared from
+   every report for a week.
+2. A process-wide cooldown opens: `Retry-After` when present (delta or date, capped at 120 s),
+   otherwise 30 s. During the cooldown every NVD call fails fast with `Throttled` - no wait, no
+   retry chain. Worst case added latency per cooldown window is one Polly chain (~7.5 s), never
+   a per-item stall; the nightly refresh breaks out of its loop on the first throttled answer and
+   reports the remainder as `cveSkippedThrottled`.
+3. Not done on purpose: no in-process retry beyond Polly, no VulnCheck-style mirror, no separate
+   "throttled" cache state. Hard-expired cache rows keep serving while NVD is unavailable
+   (better than nothing, logged); a product with no row at all is reported without CVE data for
+   that run and gets a real attempt on the next correlation.
+
+# Nightly sync (`VulnerabilityDataSync`, 03:00 UTC) and the manual buttons
+
+1. KEV catalog refresh (blob mirror updated).
+2. MSRC index refresh (last six Patch Tuesdays).
+3. NVD refresh of cache rows older than 7 days (sequential, breaks on throttle).
+4. **EPSS re-score of every `cve_*` row** - all ids batched through FIRST, only rows whose score /
+   percentile / date changed are rewritten (with their original `CachedAt`). A missing id in the
+   response keeps yesterday's score: a failed batch never erases data.
+
+Steps 3 and 4 live in `VulnerabilityCacheRefreshService` (singleton, one in-flight slot per walk),
+which the timer and the Global-Admin buttons share, so a manual run writes exactly what the nightly
+run writes. Four endpoints, one per source, each with its own "Last … Sync" line on the admin page
+(`GET vulnerability/sync-status`):
+
+| Button | Endpoint | Shape | Timestamp |
+| --- | --- | --- | --- |
+| Sync KEV | `POST vulnerability/sync` | synchronous | `VulnerabilityDataLastSyncUtc` |
+| Sync MSRC | `POST vulnerability/sync-msrc` | synchronous | `MsrcLastSyncUtc` |
+| Refresh NVD Cache | `POST vulnerability/sync-nvd` | **202 + background** (minutes, NVD-rate-limited); 409 while running; the page polls `nvdRefreshRunning` / `nvdLastRun` every 10 s | `NvdCacheLastRefreshUtc` - stamped only for a walk that reached every stale row (no throttle cut-off) |
+| Sync EPSS | `POST vulnerability/sync-epss` | synchronous (seconds); 409 while running | `EpssLastSyncUtc` |
+
+The timer skips a walk whose slot a manual run currently holds (`cveSkippedBusy` in telemetry)
+rather than queueing a duplicate. `nvdLastRun` / `epssLastRun` are in-memory on the answering
+instance (null after a cold start); the persisted timestamps are the durable signal.
+
+Telemetry event `VulnerabilityDataSyncCompleted` carries `epssRows / epssCves / epssScored /
+epssRowsRewritten / epssError` next to the KEV / MSRC / CVE counters; the manual EPSS run emits
+`ManualEpssSyncCompleted`.
+
+# Examples
+
+* Chrome 126 finding: `CVE-2024-4947` CVSS 8.8 HIGH, `AV:N/AC:L/PR:N/UI:R`, KEV yes -> `priority =
+  act`, riskLevel `critical` (KEV) - unchanged severity semantics, priority now explicit.
+* A 5.5 MEDIUM local-privilege CVE with EPSS 0.31 -> `attend`; the same CVE with EPSS 0.004 ->
+  `track`. Same severity band, different order of work.
+* Nightly sync while NVD throttles: `[VulnSync] NVD throttled - leaving 37 stale entries for the
+  next run`, then `[VulnSync] EPSS refresh: 1412/1450 CVEs scored across 212 rows, 180 rows
+  rewritten` - EPSS is independent of NVD's mood.
+
+# Not done (recorded)
+
+* **ExploitDB CSV** as a "public exploit exists" flag (static file, daily, same shape as the KEV
+  mirror) - useful, cheap, deliberately not added: four primary sources are enough for now and
+  each additional outbound dependency is a trust-page line. Revisit if customers ask "is there a
+  public exploit?".
+* GitHub / Nuclei PoC search, composite 0-100 risk scores, CWE -> ATT&CK mapping - noise for an
+  Intune admin, not adopted.
+
+# Citations
+
+* `src/Backend/AutopilotMonitor.Functions/Services/Vulnerability/NvdApiClient.cs` - `NvdFetchResult`, cooldown, `ComputeCooldown`
+* `src/Backend/AutopilotMonitor.Functions/Services/Vulnerability/EpssApiClient.cs` - batching, `ParseResponse`
+* `src/Backend/AutopilotMonitor.Functions/Services/Vulnerability/CvePriority.cs`
+* `src/Backend/AutopilotMonitor.Functions/Services/Vulnerability/VulnerabilityCorrelationService.cs` - `ProjectNvdResponse`, `ApplyEpssScores`, `BuildCveCacheRow`, `StampFindingPriority`, `FetchAndCacheCvesFromNvdAsync`
+* `src/Backend/AutopilotMonitor.Functions/Functions/Vulnerability/VulnerabilityDataSyncFunction.cs` - `RefreshStaleCveCacheAsync`, `RefreshEpssScoresAsync`
+* `src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.AgentApi.cs` - `BuildCveIndexEntities`, `ScanCveIndexAsync`
+* `src/Backend/AutopilotMonitor.Functions.Tests/EpssAndNvdThrottleTests.cs`
+* FIRST EPSS API: https://api.first.org/epss/ - CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

docs/index.md

@@ -35,6 +35,7 @@ https://docs.autopilotmonitor.com (separate repository).
 * [System Timeline Watcher](agent/system-timeline-watcher.md) - Ground truth for two timeline blind spots from one System-channel EventLogWatcher with pre-agent backfill: system_clock_changed (Kernel-General 1 — oldTime/newTime/signed timeDeltaMs/reason/setting process; 2 s micro-slew floor, ≥5 min Warning+immediate) and system_sleep_episode (Power-Troubleshooter 1 sleep/hibernate + Kernel-Power 507 Modern Standby; authoritative enteredAt/exitedAt payload instants, 60 s Modern-Standby floor). Consumed by the TimeJumpBadge clock-set cause, the SessionInfoCard standby note, time-attribution SleepSpans (AttributionVersion 3) and ANALYZE-DEV-012.
 * [DO GroupId Auto-Set](agent/do-group-id-auto-set.md) - EnableDoGroupIdAutoSet (ConfigVersion 40): the agent seeds the Delivery Optimization DOGroupId policy with a deterministic network-fingerprint GUID (default gateway IPv4 + SendARP MAC, RealmJoin-compatible byte layout) so same-network devices form one DO peering group during ESP; ownership-tracked via the StartupEventGate fingerprint, foreign DOGroupId/DOGroupIdSource policies always win, no random-GUID fallback.
 * [ESP Policy-Provider Stall Detection](agent/esp-policy-provider-stall.md) - The EnrollmentStatusTracking CSP's no-timeout Setup/Apps wait is keyed to the Intune-registered "Sidecar" provider by NAME: co-management's "ConfigMgr" parks the user ESP at "Apps (Identifying)" for days even with TrackingPoliciesCreated=1 (issue #106); the always-on two-arm esp_policy_provider_stalled tripwire (provider_incomplete | sidecar_provider_missing) and the SOFTWARE\Microsoft\Windows\Autopilot gather-rule allowlist entry that surface it.
+* [WiFi SSID and the Windows 24H2 Location Gate](agent/wifi-ssid-location-gate.md) - Why wifi_signal_info vanished on Windows 11 24H2+: WlanQueryInterface(wlan_intf_opcode_current_connection) is gated behind precise-location consent, the prompt only fires in a user context outside System32, and SYSTEM in session 0 falls back to the device-level ConsentStore value - so netsh (same gate) could never cover for it. The tiered WifiInfoProvider (native, then ungated WinRT GetConnectedSsid, then netsh), SSID-only semantics on tier 2, and the Warning-level rc=5 diagnostic that names the gate.
 
 # Rules
 
@@ -58,6 +59,7 @@ https://docs.autopilotmonitor.com (separate repository).
 * [Rule Regression Radar](backend/rule-regression-radar.md) - How analyze-rule hit-rate regressions are detected (7-day window ≥2× the 28-day baseline with disjoint Wilson intervals), which suppressions keep the radar quiet (grace period, edit-in-window, kill switch), how alert episodes live in the ruleregression tracker keyspace with re-arm semantics, and the on-fire dimension correlation with its "correlated, not necessarily causal" wording contract.
 * [Verdict Calibration](backend/verdict-calibration.md) - How every session status write declares its VerdictPath (origin:detail vocabulary incl. classifier rule ids), how overriding a verdict preserves PriorStatus/PriorVerdictPath as the correction stream, the daily per-path calibration aggregate with the 7-day re-enrollment proxy and read-side legacy derivation, the GA endpoint / MCP tool / admin matrix, and the drift radar (share, silence-share, r6 evidence gap) with its operator-only ops events.
 * [App Version Duration Regression Radar](backend/app-version-regression-radar.md) - How app versions whose median install duration regressed vs. the previous version are detected (first-seen-ordered versions, median lift ≥2× plus a 5-minute absolute floor over measured installs only), how alert episodes live in the appversionregression tracker keyspace with drain/median re-arm semantics, and the bell/ops-event/analytics surfaces.
+* [Session Owner Binding](backend/session-owner-binding.md) - Agent endpoints authenticate per tenant but write per caller-supplied session id; each Sessions row is now bound to the device identity that created it (cert thumbprint + Intune device id from the CN, or bootstrap code + serial), the rule matrix that keeps restart / WhiteGlove Part 2 / bootstrap→cert handoff / cert re-issue working, the shadow telemetry (`SessionOwnerBinding` request dimension, `AgentSessionOwnerBinding` warning, `SessionOwnerMismatch` ops event), and the enforcement contract where a 403 `session_owner_mismatch` makes the agent rotate its session id instead of counting an auth failure.
 * [Plan Downgrade Policy & the Retention Grace Period](backend/plan-downgrade-retention-grace.md) - What happens when a tenant loses Pro: every entitlement gates read-time and reversibly ("gate, don't destroy"), except retention — a 30-day grace keeps the Pro cap before the Community cap starts hard-deleting; the ProDowngradedUtc/trial-expiry anchor model, the TenantPlanDowngraded/RetentionGrace* ops events, and the deliberate non-grace of everything else.
 * [Tenant Activation & the Once-Only Welcome Mail](backend/tenant-activation-welcome-mail.md) - How a signup becomes an activated tenant (manual approve or the auto-approve queue), and the write-then-read + conditional-marker arbitration that sends the welcome mail exactly once even though activation and the user-typed notification address race each other.
 * [W365 Cloud PC Device Validation](backend/cloudpc-device-validation.md) - Why Cloud PCs can never pass the Autopilot serial lookup, and the cert-CN-bound CloudPc fallback validator: Subject CN (= Intune device id) matched against the tenant's Graph virtualEndpoint/cloudPCs inventory — admits exactly the service-provisioned Cloud PCs, nothing else.
@@ -67,6 +69,7 @@ https://docs.autopilotmonitor.com (separate repository).
 
 # MCP Server
 
+* [MCP Protocol Eras & Client ID Metadata Documents](mcp/protocol-eras-and-cimd.md) - One per-request factory serving the 2026-07-28 stateless revision (server/discover, ttlMs/cacheScope, Mcp-Method routing) and 2025-era initialize clients side by side, why the legacy leg stays a hand-wired JSON+gzip transport, the never-public cache-hint contract, and the CIMD client-registration path (SSRF-gated document fetch, same redirect allowlist) next to the deprecated dynamic registration.
 * [MCP Docs Corpus](mcp/docs-corpus.md) - How the published customer documentation becomes the `search_docs` corpus: CRLF-safe heading chunking, build-time embedding as a third precomputed section, and why a docs edit needs an MCP redeploy.
 * [MCP Tool Telemetry](mcp/tool-telemetry.md) - The three telemetry layers for judging tool quality: backend App Insights via X-MCP-Tool-Name, the per-user usage table, and the MCP_TOOL_LOGGING stderr lines (soft errors, result size vs. cap, zero-hit searches, Zod rejections).
 
@@ -77,7 +80,10 @@ https://docs.autopilotmonitor.com (separate repository).
 # Security & Identity
 
 * [MCP OAuth Flow](mcp-oauth-flow.md) - Who authenticates where when connecting an AI client to the MCP server; two identities, three parties plus Entra ID.
-* [Client-Certificate Tenant Binding](backend/client-cert-tenant-binding.md) - Why a chain-valid Intune MDM certificate only proves "issued to some tenant", which extension actually carries the Entra tenant id (`…5.14`) versus the two that look like it (`…5.6` Intune Account id, `…5.4` device id, different encodings), why the Entra join certificate is not part of the auth path, and the shadow-then-enforce rollout with its volume-controlled telemetry.
+* [Vulnerability Correlation Sources](backend/vulnerability-correlation-sources.md) - How the software inventory becomes CVE findings from four cached primaries (NVD per-CPE cache with budget and TTLs, CISA KEV, MSRC, FIRST EPSS stored on the cached CVE and re-scored nightly), the NVD throttle contract (a refused answer is never cached as "0 CVEs"; bounded process-wide cooldown honouring Retry-After), the persisted CVSS vector, and the act/attend/track priority that keeps severity and likelihood as two visible signals instead of one composite score.
+* [Client-Certificate Tenant Binding](backend/client-cert-tenant-binding.md) - Why a chain-valid Intune MDM certificate only proves "issued to some tenant", which extension actually carries the Entra tenant id (`…5.14`) versus the two that look like it (`…5.6` Intune Account id, `…5.4` device id, different encodings), why the Entra join certificate is not part of the auth path, the shadow-then-enforce rollout with its volume-controlled telemetry, and why `X-ARR-ClientCert` is the only certificate transport (TLS handshake = proof of possession; bootstrap routes token-only, fail-closed).
+* [Admin Identity Binding](backend/admin-identity-binding.md) - Why a GlobalAdmins / DelegatedAdmins row keyed on a UPN string must never confer access by itself in an API that accepts tokens from every Entra tenant (domain re-registration, UPN recycling), the AdminIdentityBindings table pinning each cross-tenant-role UPN to its immutable home tid + oid, the fail-closed resolution order in both role services (row → binding → entitlement), the first-sign-in object-id pin with its race semantics, the 409 on grant-time conflicts, and the explicit GET/PUT/DELETE rebind surface.
+* [IME Installer Archive](backend/ime-msi-archive.md) - How every fleet-observed IME build is archived as its MSI: the ime_agent_version sighting that queues the job (first sighting, or a later sighting with a version-authoritative CSP URL after a 24 h backoff), the primary/secondary/hotfix candidate walk, the managed MSI ProductVersion check that keeps another ring's build out of the version folder (Failed:VersionMismatch), provenance with the full candidate walk, and the skill-side overwrite path for corrections.
 
 # Conventions for this bundle
 

docs/log.md

@@ -1,5 +1,75 @@
 # Log
 
+## 2026-08-29 (9)
+
+* **Update**: `agent/decision-engine.md`, `agent/overview.md` — `SignalIngress.Post` is worker-thread re-entrancy-safe: signals the worker posts to itself from inside `ApplyStep` (EffectRunner `ClassifierVerdictIssued`) go to a worker-local follow-up queue drained ahead of the bounded channel instead of blocking on it, so a full channel can no longer deadlock the single consumer.
+
+## 2026-08-29 (8)
+
+* **Creation**: Added `backend/session-owner-binding.md` — SESSION-OWNER-BINDING stage 1 (shadow): Sessions rows carry the creating device identity (`OwnerKind/OwnerThumbprint/OwnerDeviceId/OwnerBootstrapCode/OwnerSerial/OwnerBoundAt`, primary-only), `SessionOwnershipPolicy` evaluates every register / telemetry / error-report request against it, outcomes ride on the request row (`SessionOwnerBinding`), warnings and a throttled `SessionOwnerMismatch` ops event; nothing is refused yet. Agent ships the dormant counterpart: `errorCode` parsing on 401/403, one-shot session rotation on `session_owner_mismatch` without feeding the auth-failure tracker, spool drop, `agent_started.sessionRotated`.
+
+## 2026-08-29 (7)
+
+* **Update**: `backend/client-cert-tenant-binding.md` — new "Certificate transport and proof of possession" section: `X-ARR-ClientCert` (platform-set after the mTLS handshake, inbound copies stripped even on excluded paths) is the only certificate source; the client-writable `X-Client-Certificate` fallback is gone; `/api/bootstrap/*` routes are token-only and fail closed on a missing/empty token or unwired token service instead of falling through to the certificate stage.
+
+## 2026-08-29 (6)
+
+* **Update**: `backend/admin-identity-binding.md` — grants are self-maintaining: `AdminIdentityResolver` derives the home tenant + object id from sign-in history (`UserActivity`), falls back to the UPN domain of an onboarded tenant, refuses to guess when a UPN was seen under two tenants; 422 `HomeTenantUnresolved` + portal tenant picker only for a never-seen domain. Identity fields and pills removed from the delegated / tenant-group forms; inspect/correct lives in Tenant Management → Edit Tenant Configuration → Identity bindings (collapsed).
+
+## 2026-08-29 (5)
+
+* **Creation**: Added `backend/admin-identity-binding.md` — cross-tenant roles (GlobalAdmin / GlobalReader, delegated MSP) were resolved from the UPN string alone while the API accepts tokens from every Entra tenant. New `AdminIdentityBindings` table (RK = UPN → home `TenantId` + `ObjectId`), `AdminIdentity` (upn + tid + oid) as the key both role services resolve on, binding checked after the row and before the Pro gate, object id pinned on the first sign-in from the bound tenant (ETag-guarded), grants require `homeTenantId` and refuse to re-home (409), `global/identity-bindings` GET/PUT/DELETE as the audited rebind path, `RequestContext.ObjectId`, throttle bucket keyed on oid. Legacy rows are inert until bound — seed bindings before the backend deploy.
+
+## 2026-08-29 (4)
+
+* **Creation**: Added `backend/ime-msi-archive.md` — the version-verified, multi-host IME installer archive: MsiProductVersionReader (managed CFB/MSI Property reader), candidate host walk, Failed:VersionMismatch, sighting re-queue with 24 h backoff, and the 2026-08-29 1.105.103.0 poisoning that motivated it.
+
+## 2026-08-29 (3)
+
+* **Update**: `backend/vulnerability-correlation-sources.md` - the admin page's Data Sync Status is complete: next to Sync KEV / Sync MSRC there are now Refresh NVD Cache and Sync EPSS, each with its own last-sync line (`NvdCacheLastRefreshUtc`, `EpssLastSyncUtc` on AdminConfiguration; shared manifest regenerated). The NVD and EPSS walks moved out of the timer into `VulnerabilityCacheRefreshService` (singleton, one in-flight slot per walk) so the button and the nightly run are literally the same code; the NVD walk is minutes long and rate-limited, so `POST vulnerability/sync-nvd` answers 202 and the page polls `sync-status` (`nvdRefreshRunning`, `nvdLastRun`) while it runs, `sync-epss` runs synchronously. 409 while a walk is in flight; the timer skips a slot a manual run holds. Operator-only surface - no customer docs.
+
+## 2026-08-29 (2)
+
+* **New**: `backend/vulnerability-correlation-sources.md` - FIRST EPSS joins NVD / CISA KEV / MSRC as the fourth vulnerability source: the probability + percentile + date live on the cached CVE (one batch of <= 100 ids per CPE fill, every `cve_*` row re-scored by the nightly sync, only changed rows rewritten and with their original `CachedAt`), the CVSS vector is persisted instead of dropped, and each CVE carries an act / attend / track priority (KEV; EPSS >= 0.1 or CVSS >= 9.0; rest) next to the unchanged severity bands - two visible signals, no composite score. The comparison with an open-source CVE MCP server surfaced the real 429 defect: Polly already retried, but a refused NVD answer came back as an empty response and was cached as "0 CVEs" for seven days. `NvdFetchResult` now separates "answered" from "refused" (nothing persists a refusal - CPE cache, negative auto-resolve cache, admin auto-resolve), and a 429 opens a process-wide cooldown (`Retry-After` capped at 120 s, else 30 s) so the run fails fast instead of paying a retry chain per software item; hard-expired rows keep serving meanwhile. NVD -> cache projection and the row builder are now single functions shared by the live fill and the sync. CveIndex / fleet summary carry `epssScore` + `priority`; portal shows EPSS pill, priority pill, vector; MCP tool descriptions and the CVE-audit prompt name the fields. ExploitDB recorded as a deliberate not-now. Backend before web; trust pages (terms attribution, privacy, data-flows), settings and portal-guide docs updated in the same change.
+
+## 2026-08-29
+
+* **New**: `mcp/protocol-eras-and-cimd.md` - the MCP server moved to the 2026-07-28 protocol revision (TypeScript SDK v2: `@modelcontextprotocol/server` + `/node`, zod 4; the monolithic `@modelcontextprotocol/sdk` is gone). One per-request factory (`mcp-server-factory.ts`) feeds both eras through `mcp-http.ts`: 2026 clients are served by the SDK entry (`createMcpHandler`, `legacy: 'reject'`, JSON response mode), 2025 clients keep the existing stateless transport with `enableJsonResponse` - routed on the SDK's own `isLegacyRequest` predicate, because the built-in stateless fallback would answer today's Claude/VS Code clients with SSE and lose the gzip win. Capabilities now declare `listChanged: false` (the SDK default advertised a notification a per-request server cannot send); `cacheHints` stamp `ttlMs`/`cacheScope: 'private'` on discover/list results (5 min) and resource reads (60 min) - never public, the catalog is role-dependent. Client registration: `client_id_metadata_document_supported: true`; an https `client_id` is a Client ID Metadata Document resolved by `cimd.ts` (SSRF gate on the resolved addresses before any request, no redirects, 5 s / 16 KB, exact `client_id` match, bounded `redirect_uris`, 10-60 min cache), the requested redirect_uri still has to pass the dynamic-registration allowlist; HMAC-signed DCR client_ids stay as the fallback. `mcp-oauth-flow.md` updated. Package version 1.5 -> 1.6. Pinned by `mcp-http.test.ts` (real v2 client over loopback HTTP, both eras, role parity), `cimd.test.ts`, `oauth-cimd.test.ts`.
+
+## 2026-08-28
+
+* **Update**: `CmTraceSkewTripwire` - the backend regression tripwire additionally requires >= 80 % of the individual IME deltas (relative to the other side's median) to sit within 2 min of some 15-minute grid multiple before `CmTraceTimeSkewRegression` fires; the ops event and its details now carry that fraction. Motivation: the first soak week produced 7 fires, all backlog replays - a relaunched agent re-tailing the IME log uploads one burst holding most of the session's IME samples with a continuum of ages whose median hit the grid by chance (session d832560a: 508 of 627 samples, 46...733 min, median 91). Era-mixing regressions (every line on the grid) still fire. Doc: `docs/agent/cmtrace-time-resolution.md`.
+
+## 2026-08-27 (2)
+
+* **Update**: `SecurityValidator` / `DeviceAssociationValidator` - Microsoft released Windows Autopilot device association on 2026-08-25 (learn.microsoft.com/autopilot/device-preparation/device-association/overview: TPM-backed UEFI marker, device-targeted device preparation policies, associated devices are marked corporate-owned by Intune with no corporate identifier upload). The DevPrep association lookup therefore leaves shadow mode and becomes the third accepting method of the device-validation gate, evaluated inline after the Autopilot and Corporate Identifier lookups and before the Cloud PC fallback; a match sets `ValidatedBy = DeviceAssociation`, a miss joins the combined 403 detail, a transient failure the 503 Retry-After - the same contract as its siblings, so enabling it can only widen acceptance, never reject a device the other methods would have taken. `ValidateDeviceAssociation` counts toward "at least one validation enabled" and is no longer GA-only anywhere (`UpdateTenantConfigurationFunction` revert, `TenantConfigPatchService.GaOnlyFields`, the Global-Admin gate on the settings toggle); the toggle sits under Device Preparation next to Corporate Identifier and follows the shared consent rule (first serial-based validation carries the consent, any further one is a plain persisted toggle). Known gap carried over from the shadow phase: the `/beta/deviceManagement/tenantAssociatedDevices` endpoint is still undocumented in Graph reference and every production lookup so far answered `matched=False` for Autopilot v1 devices, i.e. the positive match path is unproven in the field - first associated enrollment must be checked for `ValidatedBy = DeviceAssociation` on the session row. Landing hero carries a release pill linking to the customer docs; dashboard tip added. Backend before web; customer docs updated in `autopilotmonitor-docs`.
+
+## 2026-08-27
+
+* **Update**: `backend/silent-session-classification.md`, `backend/verdict-calibration.md` - the first real calibration read tuned what it measures. Rule 5 grew a past-grace fork 5a: Device Setup done + real-user desktop + zero `app_install_failed` reconciles to Succeeded "completed (assumed)" (`r5_assumed`) - r5-Incomplete devices re-enrolled at 2.6 %, the succeeded background, and the sampled desktop half had clean app records; no desktop or any failed app stays Incomplete. The max-lifetime watchdog (either event shape) now skips the AwaitingUser grace entirely - all five observed maxlife parks expired unhealed, and late telemetry heals a terminal verdict anyway - while WhiteGlove rule 1b keeps its park (its one episode healed). The drift radar got floors (≥ 10 window hits; per-path share regression needs ≥ 5 baseline hits, so new/renamed vocabulary cannot "regress") and legacy continuity: rule-shaped `legacy:*` paths count into the silence and classifier-verdict group sums on both sides of the 2026-08-23 cutover, which dissolves the lift-124 silence artifact and lets sub-floor episodes clear themselves. Backend only; the new path shows up in the matrix on its own.
+
+* **Update**: `backend/tenant-activation-welcome-mail.md` - the reverse lookup. A delivery log names only the recipient, so an address had to lead back to its tenant: the tenant console's search now matches the notification and contact address as well as domain and tenant id, with the quoted exact mode unchanged. The addresses sit in `PreviewWhitelist`, not on the tenant config, so a new GA/Reader-only `GET /api/preview/notification-emails` returns them as one map (single cross-partition scan of `RowKey eq 'notification-email'`) instead of a point read per tenant; both sides join on the lowercased tenant id because the address rows carry the JWT `tid` while a config PartitionKey's casing is not guaranteed, and matching is case-insensitive because stored addresses keep the casing the user typed. The map is best-effort in the portal - a failed read costs only the search-by-address, never the tenant list - and the addresses stay out of the list rows (search key, not a column). Match rules moved into `tenantSearch.ts` with unit pins. Backend before web.
+
+
+## 2026-08-26
+
+* **Update**: `agent/wifi-ssid-location-gate.md` - the network timeline now explains its blank signal too, with no agent change: `buildSegments` already merges `wifi_signal_info` into the covering WiFi segment, so `wifiDataLimitedReason` rides in with the sample. Segments that never got a sample (a mid-session reconnect emits none) inherit it - the gate is a device-level setting and cannot flip mid-enrollment - while a segment with a real reading is never overwritten. Tooltip shows `Signal: unavailable - Location services off on this device`; the "Avg WiFi signal" stat reads `n/a (Location services off)` instead of vanishing. `network_state_change` is deliberately left alone: it has never carried `signalPercent` or `radioType` (only `before_/after_wifiSsid` reaches its payload), so there is no absent field there for a reason to explain, and the SSID it does carry is unaffected by the gate. Web-only change.
+
+
+## 2026-08-26
+
+* **Update**: `agent/wifi-ssid-location-gate.md` - the gate is now surfaced instead of only logged. When the WinRT tier wins and the native tier reported `rc=5`, `wifi_signal_info` carries `wifiDataLimitedReason = "location_services_off"` and the message gains `- signal unavailable, Location services off`, so the reason is readable straight from the timeline; the portal WiFi card (`DeviceDetailsCard`) matches that literal and names the Intune setting that restores the full payload. The claim is evidence-only - any other native failure leaves the field null rather than blaming a privacy setting, with `IsLocationGateDenied` pinned at its boundaries. New `wifi_signal_info` group in the MCP `DEVICE_PROPERTIES_CATALOG` so a fleet can be sized via `search_sessions` before any policy changes. Agent release + web deploy + MCP redeploy; backend untouched (the payload is opaque DataJson).
+
+
+## 2026-08-26
+
+* **New**: `agent/wifi-ssid-location-gate.md` - `wifi_signal_info` was missing on most Windows 11 24H2+ WiFi enrollments (build 22631 3/3, 26100 37/178, 26200 43/95 over n=276 sessions from 08-01). Not a parser or language problem: every event that exists carries a full SSID, so the failure is binary at the reader. Cause is the 24H2 location gate on `WlanQueryInterface` with `wlan_intf_opcode_current_connection` - the only opcode the agent uses - which returns `ERROR_ACCESS_DENIED`; the consent prompt only fires for a process in the user context outside `System32`, so the agent (SYSTEM, session 0, pre-privacy-page) is denied silently, and it resolves consent from the HKLM ConsentStore because the `S-1-5-18` hive has none - while the interactive user on the same box reads the SSID fine via the per-user NonPackaged value. `netsh wlan` hangs off the same gate, so the 2026-07 netsh fallback (and its multi-language labels) never covered the case it was built for; more labels cannot fix it. New `WinRtWifiSsidReader` uses the documented replacement `WlanConnectionProfileDetails.GetConnectedSsid` (ungated, SSID only), bound via the CLR WinRT projection with no winmd/NuGet like `OobeStateReader`; new `WifiInfoProvider` owns the tier order (native, WinRT, netsh) that both collectors had duplicated. The step diagnostics added in 2026-07 were logged at `Debug` while the default level is `Info`, so they never reached a field log - the all-tiers-failed case is now a Warning that decodes `rc=5` into the location-gate explanation. Agent-only change; needs an agent release.
+
+
+## 2026-08-25
+
+* **Update**: `backend/client-cert-tenant-binding.md` — stage 2 enforced: `Mismatch` now returns 403 via `LogRequestRejection(stage=certtenant)`. Switched on against 35,684 requests / 32 tenants at 100 % `Match`, with the Warning channel verified to be carrying other traffic so the zero was not an artefact. The rule is one function (`CertTenantBinding.Rejects`) and only `Mismatch` blocks; `ExtensionMissing` / `Unparseable` / `RequestTenantNotAGuid` are tolerated on purpose (the first is the candidate for later tightening and has a test pinning the tolerance). Evaluation fails open on its own exception, and the 403 body does not echo the certificate's tenant. Device binding (stage 3) stays shadow + Global-Admin-only and is unaffected.
+
 ## 2026-08-25
 
 * **New**: `agent/zero-user-apps-completion-gate.md` — a Classic enrollment whose user has zero targeted Intune Win32 apps could not produce the evidence any user-phase completion path required: IME's zero-app branch (`ApplicationPoller`, verified against decompiled 1.104.102.0 and three older builds) `continue`s before its `Completed user session` statement, so `ImeUserSessionCompletedUtc` stayed null, all four arms of `ShouldTransitionToAwaitingHello` were dead, and the 30-min `advisory_completion` backstop resolved the session as `esp_exit_without_completion_evidence` — with a DAD-validated desktop, Hello provisioned and RealmJoin still installing. One tenant: 10 of 30 enrollments in a week, all false positives. Two fixes. (1) New pattern `IME-USER-SESSION-ZERO-APPS` reads the line IME *does* write and routes it through the same `OnUserSessionCompleted` callback, guarded to the AccountSetup phase and replayed if the observation predates the phase marker; `AreUserEspAppsSettled` now accepts an empty app list only with that explicit observation. (2) `HandleAdvisoryCompletionDeadlineFired` re-arms instead of failing while the RealmJoin gate is closed and its own deadline is still armed — session 75d6ae8e installed 25 RealmJoin packages inside the window, the last 2 min before the failure. `ime_user_session_completed` gains an `evidence` field (`zero_user_apps_enumerated` / `user_session_completed`); no new event type. The pattern reaches existing agents via the config API (an unknown action is a Debug line), the behaviour needs an agent release.

docs/mcp-oauth-flow.md

@@ -8,7 +8,7 @@ tags:
   - oauth
   - entra-id
   - security
-timestamp: 2026-07-11T10:59:31+02:00
+timestamp: 2026-08-29T08:45:00+02:00
 ---
 
 # MCP OAuth Flow — Who Authenticates Where
@@ -41,9 +41,12 @@ The two identities never mix:
    in the vendor's backend, not on the user's machine.
 2. **MCP server** (Container App) — acts as a stateless **OAuth proxy /
    authorization-server façade** in front of Entra ID. It is *not* an IdP:
-   it registers clients dynamically (RFC 7591, HMAC-signed stateless
-   `client_id`), enforces the redirect-URI allowlist and PKCE, and exchanges
-   codes at Entra using its confidential client secret.
+   it establishes the client's identity statelessly — a Client ID Metadata
+   Document (MCP spec 2026-07-28: the `client_id` is an HTTPS URL the server
+   fetches and validates) or, for older clients, dynamic registration
+   (RFC 7591, HMAC-signed stateless `client_id`) — enforces the redirect-URI
+   allowlist and PKCE, and exchanges codes at Entra using its confidential
+   client secret. See [Protocol Eras & CIMD](mcp/protocol-eras-and-cimd.md).
 3. **Entra ID** — the real identity provider. This is where `adm.luke` lives.
 
 ## Full sequence
@@ -54,9 +57,10 @@ Claude Desktop        Browser (user's           MCP server              Entra ID
      │                      │                        │                      │
  1.  │─ POST /mcp ──────────┼───────────────────────▶│ 401 + WWW-Auth       │
  2.  │─ Discovery ──────────┼───────────────────────▶│ RFC 9728/8414 docs   │
- 3.  │─ POST /oauth/register┼───────────────────────▶│ client_id (HMAC-     │
-     │                      │                        │ signed, embeds the   │
-     │                      │                        │ registered callback) │
+ 3.  │─ client identity ────┼───────────────────────▶│ CIMD: client_id is a │
+     │   (CIMD, or legacy   │                        │ URL, doc fetched at  │
+     │    POST /oauth/      │                        │ /authorize; DCR:     │
+     │    register)         │                        │ HMAC-signed client_id│
      │                      │                        │                      │
  4.  │─ opens browser ─────▶│─ GET /oauth/authorize ▶│─ 302 to Entra ──────▶│
      │                      │  (PKCE challenge)      │  app-reg client_id,  │

docs/mcp/protocol-eras-and-cimd.md

@@ -0,0 +1,129 @@
+---
+type: Concept
+title: MCP Protocol Eras & Client ID Metadata Documents
+description: How the MCP server serves the 2026-07-28 stateless revision and 2025-era clients from one per-request factory, why the legacy leg is hand-wired (JSON + gzip), the cache-hint and capability contract, and the CIMD client-registration path next to the deprecated dynamic registration.
+resource: /src/McpServer/autopilot-monitor-mcp/src/mcp-http.ts
+tags:
+  - mcp
+  - protocol
+  - oauth
+  - cimd
+  - security
+timestamp: 2026-08-29T08:40:00+02:00
+---
+
+# MCP Protocol Eras & Client ID Metadata Documents
+
+**Status:** Concept · **Owner:** MCP Server · **Code:** [`mcp-http.ts`](../../src/McpServer/autopilot-monitor-mcp/src/mcp-http.ts), [`mcp-server-factory.ts`](../../src/McpServer/autopilot-monitor-mcp/src/mcp-server-factory.ts), [`cimd.ts`](../../src/McpServer/autopilot-monitor-mcp/src/cimd.ts), [`oauth.ts`](../../src/McpServer/autopilot-monitor-mcp/src/oauth.ts)
+
+# Schema
+
+## The two eras
+
+MCP revision **2026-07-28** turned the protocol into a stateless request/response
+protocol: no `initialize` handshake, no `Mcp-Session-Id`, every request carries its
+protocol version, client identity and capabilities in `_meta`, capabilities and
+instructions are fetched with `server/discover`, list results carry `ttlMs` /
+`cacheScope`, and `Mcp-Method` / `Mcp-Name` HTTP headers let gateways route without
+parsing bodies. Roots, Sampling, Logging and the HTTP+SSE transport are deprecated
+(twelve-month window); Dynamic Client Registration is deprecated in favour of Client
+ID Metadata Documents.
+
+The server was already stateless by design (scale-to-zero Container App, no
+server→client traffic), so the revision cost no architecture — only wiring:
+
+| Concern | 2026-07-28 ("modern") | 2025-era ("legacy") |
+| --- | --- | --- |
+| Routing decision | `isLegacyRequest()` from the SDK — the exact classifier `createMcpHandler` uses internally | same predicate, inverse |
+| Serving | `createMcpHandler(factory, { legacy: 'reject', responseMode: 'json' })` via `toNodeHandler` | fresh `NodeStreamableHTTPServerTransport({ sessionIdGenerator: undefined, enableJsonResponse: true })` per POST |
+| Response shape | single `application/json` body | single `application/json` body |
+| Instructions | `server/discover` result | `initialize` result |
+| Cache fields | `ttlMs` + `cacheScope` stamped by the SDK from `cacheHints` | none (2025 codec has no cache path) |
+
+Both legs are fed by **one** factory (`createServerForCaller`), so the tool catalog,
+resource set, prompts and instructions can never drift between eras — the
+`mcp-http.test.ts` suite pins that a Global Admin and a plain tenant user see the
+same catalog on either path.
+
+## Why the legacy leg is hand-wired
+
+`createMcpHandler`'s built-in `legacy: 'stateless'` fallback constructs its transport
+with only `sessionIdGenerator: undefined`, i.e. it answers every 2025 client with an
+SSE frame. Every production client today (Claude Code, Claude.ai, VS Code) is a 2025
+client, and their large tool results are gzipped by the compression middleware only
+because the response is a plain JSON body (measured 5–30×). Routing on the SDK's own
+predicate in user land keeps that behaviour while still running the 2026 path through
+the SDK entry unchanged — no re-implementation of the classification, no second
+catalog.
+
+## Capability and cache contract
+
+* `capabilities` are declared explicitly with `listChanged: false` for tools,
+  resources and prompts. The SDK's default (`?? true`) would advertise a
+  notification a per-request server can never emit.
+* `cacheHints`: `server/discover`, `tools/list`, `prompts/list`, `resources/list`,
+  `resources/templates/list` → `{ ttlMs: 300_000, cacheScope: 'private' }`;
+  `resources/read` → `{ ttlMs: 3_600_000, cacheScope: 'private' }`. **Never
+  `public`**: the catalog and the instructions are role-dependent (Global Admin /
+  Global Reader / delegated MSP / tenant user), so a shared cache would leak one
+  caller's surface to another. Five minutes is the bound on how long a role change
+  can go unnoticed by a caching client; resources are static per deployment.
+* No Roots / Sampling / Logging / elicitation / subscriptions are used anywhere, so
+  nothing on the deprecation list has to be migrated.
+
+## Client registration: CIMD first, DCR as fallback
+
+The authorization-server metadata now advertises
+`client_id_metadata_document_supported: true` next to the (deprecated)
+`registration_endpoint`. Clients following the spec's priority order use a
+**Client ID Metadata Document**: their `client_id` *is* an HTTPS URL that serves a
+JSON document (`client_id`, `client_name`, `redirect_uris`, …). `oauth.ts` resolves
+every `client_id` through one helper: an HTTPS URL goes to `cimd.ts`, anything else
+must be one of our HMAC-signed dynamic-registration tokens. Both yield the same shape
+(`redirectUris`), and the rest of the authorize/callback logic is unchanged.
+
+What the document decides — and what it does not:
+
+* It only asserts **which** redirect URIs the client claims. The requested
+  `redirect_uri` must still pass the host/path allowlist that gates dynamic
+  registration (`isAllowedRedirectUri`), checked *before* the document is fetched. A
+  self-hosted document cannot widen the destinations an authorization code may be
+  sent to. Loopback remains allowed for every client (RFC 8252 §7.3);
+  `application_type: "native"` is informational.
+* Fetching a caller-chosen URL is an SSRF surface, so the fetch is: HTTPS only, path
+  component required, no fragment/userinfo, no loopback or IP-literal host, every
+  resolved address must be public (RFC 1918/4193/3927/6598, CGNAT, multicast,
+  IPv4-mapped all refused — checked before any request leaves), `redirect: 'error'`,
+  5 s budget, 16 KB body cap (declared *and* streamed), JSON media type required.
+  Nothing from the response reaches the caller beyond an OAuth error code.
+* The document's `client_id` must equal the URL by simple string comparison — no
+  normalization, per the draft. `redirect_uris` is bounded exactly like a dynamic
+  registration (`oauth-limits.ts`). A missing `client_name` falls back to the host:
+  it only ever reaches a log line, and failing a login over a label would be wrong.
+* Cache: positive entries live for the document's `Cache-Control: max-age`, clamped
+  to 10–60 min so the `/oauth/callback` re-check within the 10-min signed-state
+  window is a cache hit on the same replica; rejections are cached for 60 s; the map
+  is bounded to 256 entries.
+
+RFC 9207 `iss` (already emitted since 2026-07-29) completes the authorization side
+of the 2026-07-28 revision.
+
+# Examples
+
+* A 2026 client: `POST /mcp` with `_meta["io.modelcontextprotocol/protocolVersion"] = "2026-07-28"`
+  and `Mcp-Method: tools/list` → `{ tools: [...], ttlMs: 300000, cacheScope: "private", _meta: { "io.modelcontextprotocol/serverInfo": { name: "Autopilot-Monitor", version: "1.6.<build>" } } }`.
+* A 2025 client: `POST /mcp` `initialize` → `application/json` body with
+  `protocolVersion: "2025-11-25"` and the role-tailored `instructions`; no
+  `Mcp-Session-Id` header.
+* `GET /oauth/authorize?client_id=https://app.example.test/oauth/client.json&redirect_uri=http://127.0.0.1:49152/callback&code_challenge=…` →
+  document fetched (or served from cache) → 302 to Entra. `client_id=https://10.0.0.8/x` → `400 invalid_client`
+  without any outbound request.
+
+# Citations
+
+* MCP spec 2026-07-28 — https://blog.modelcontextprotocol.io/posts/2026-07-28/ ; authorization / client registration:
+  https://modelcontextprotocol.io/specification/2026-07-28/basic/authorization/client-registration
+* TypeScript SDK v2 (`@modelcontextprotocol/server` 2.0.0) — `createMcpHandler`, `isLegacyRequest`, `cacheHints`.
+* draft-ietf-oauth-client-id-metadata-document-00 §6 (security considerations, SSRF).
+* Tests: `src/__tests__/mcp-http.test.ts`, `src/__tests__/cimd.test.ts`, `src/__tests__/oauth-cimd.test.ts`.
+* Related: [MCP OAuth Flow](../mcp-oauth-flow.md), [MCP Docs Corpus](docs-corpus.md).

rules/analyze/ANALYZE-APP-017.json

@@ -0,0 +1,92 @@
+{
+  "$schema": "../schema/analyze-rule.schema.json",
+  "ruleId": "ANALYZE-APP-017",
+  "title": "App Install Blocked by Another Installer (0x80070652)",
+  "description": "Detects Win32 app installs that failed because the Windows Installer was busy with another installation (HRESULT 0x80070652 / MSI exit code 1618, ERROR_INSTALL_ALREADY_RUNNING). The IME retries on a fixed budget (~15-17 minutes across several attempts) and then reports the app as failed; when the app is ESP-blocking, the Device Setup Apps subcategory terminates with it.",
+  "severity": "high",
+  "category": "apps",
+  "version": "1.0.0",
+  "author": "Autopilot Monitor",
+  "enabled": true,
+  "baseConfidence": 70,
+  "conditions": [
+    {
+      "signal": "mutex_blocked_install",
+      "source": "event_type",
+      "eventType": "app_install_failed",
+      "dataField": "hresultFromWin32",
+      "operator": "equals",
+      "value": "-2147023278",
+      "required": true
+    },
+    {
+      "signal": "installer_exit_1618",
+      "source": "event_data",
+      "eventType": "app_install_failed",
+      "dataField": "exitCode",
+      "operator": "equals",
+      "value": "1618",
+      "required": false
+    },
+    {
+      "signal": "esp_failed_with_mutex_code",
+      "source": "event_data",
+      "eventType": "esp_failure_settle_started",
+      "dataField": "errorCode",
+      "operator": "equals",
+      "value": "0x80070652",
+      "required": false
+    }
+  ],
+  "confidenceFactors": [
+    {
+      "signal": "installer_exit_1618",
+      "condition": "exists",
+      "weight": 10
+    },
+    {
+      "signal": "esp_failed_with_mutex_code",
+      "condition": "exists",
+      "weight": 20
+    }
+  ],
+  "confidenceThreshold": 65,
+  "explanation": "App **{{appName}}** failed to install because the Windows Installer service was already busy with another installation — HRESULT **0x80070652** / MSI exit code **1618** (`ERROR_INSTALL_ALREADY_RUNNING`). Only one Windows Installer transaction can run at a time; the Intune Management Extension retried on its fixed budget (typically ~15-17 minutes across several attempts) and then reported the app as failed. If this app is required in the Enrollment Status Page, the Device Setup Apps subcategory fails with it and the enrollment terminates.\n\nThis failure is **deterministic per attempt**: as long as the competing installer keeps winning the race, a plain re-enrollment fails again at roughly the same minute mark — retrying without fixing the collision only churns devices.\n\nCommon sources of the competing installation:\n\n- The **preceding Win32 app in the install order**: its installer exits 0 (so IME moves on) but leaves a child `msiexec` transaction or post-install MSI work running. Security agents and proxy clients that chain multiple MSIs are frequent offenders.\n- **OEM factory software** installing on first boot (factory-image provisioning packages, vendor updaters) — typical on brand-new hardware batches.\n- **Microsoft 365 Apps (C2R), driver updaters or Windows servicing** running installations in parallel outside IME's control.",
+  "remediation": [
+    {
+      "title": "Identify the competing installer",
+      "steps": [
+        "In this session's timeline, note which app finished installing immediately before {{appName}} started — its installer is the prime suspect for holding the Windows Installer mutex",
+        "On a reproduction device, when the failure window is active, check for running installers: Get-Process msiexec | Select-Object Id,StartTime and the in-progress marker key HKLM\\SOFTWARE\\Microsoft\\Windows\\Installer\\InProgress",
+        "Check the Application event log for MsiInstaller events around the failure timestamp to see which product held the transaction",
+        "On factory-fresh hardware, also look for OEM first-boot installers (vendor updater services, factory provisioning packages) that run outside Intune"
+      ]
+    },
+    {
+      "title": "Serialize the install chain",
+      "steps": [
+        "Add an Intune Win32 dependency so {{appName}} depends on the app whose installer causes the collision — IME then orders them explicitly instead of racing",
+        "Alternatively, wrap the offending predecessor so its install script waits until msiexec has fully finished (poll the InProgress registry key or the _MSIExecute mutex with a bounded timeout) before exiting",
+        "If the app does not have to gate the ESP, remove it from the blocking-app list so a transient 1618 no longer terminates the enrollment; Intune retries it after the desktop"
+      ]
+    }
+  ],
+  "relatedDocs": [
+    {
+      "title": "Microsoft Learn: MsiExec.exe error messages (1618 = another installation is in progress)",
+      "url": "https://learn.microsoft.com/en-us/windows/win32/msi/error-codes"
+    },
+    {
+      "title": "Microsoft Learn: Troubleshoot Win32 app installations in Intune",
+      "url": "https://learn.microsoft.com/en-us/troubleshoot/mem/intune/app-management/troubleshoot-win32-app-install"
+    }
+  ],
+  "tags": [
+    "apps",
+    "msiexec",
+    "mutex",
+    "0x80070652",
+    "1618",
+    "esp"
+  ]
+}

rules/analyze/ANALYZE-NET-001.json

@@ -0,0 +1,81 @@
+{
+  "$schema": "../schema/analyze-rule.schema.json",
+  "ruleId": "ANALYZE-NET-001",
+  "title": "Diagnostics Upload Blocked by Web Security Gateway",
+  "description": "Detects diagnostics package uploads that were answered by a security appliance's HTML block page instead of the Autopilot Monitor backend. A forward proxy / secure web gateway (SWG) with SSL inspection is intercepting the upload endpoint, so exactly the sessions where diagnostics matter most (OnFailure uploads) are the ones losing them.",
+  "severity": "warning",
+  "category": "network",
+  "version": "1.0.0",
+  "author": "Autopilot Monitor",
+  "enabled": true,
+  "baseConfidence": 75,
+  "conditions": [
+    {
+      "signal": "foreign_html_response",
+      "source": "event_data",
+      "eventType": "diagnostics_upload_failed",
+      "dataField": "errorCode",
+      "operator": "contains",
+      "value": "HTML platform error page",
+      "required": true
+    },
+    {
+      "signal": "security_gateway_marker",
+      "source": "event_data",
+      "eventType": "diagnostics_upload_failed",
+      "dataField": "errorCode",
+      "operator": "regex",
+      "value": "mcafee|skyhigh|zscaler|netskope|blue ?coat|proxysg|forcepoint|websense|palo ?alto|fortigate|fortiguard|sophos|watchguard|barracuda|iboss|umbrella|lightspeed|smoothwall|contentkeeper|web ?gateway|web ?filter|content ?filter|secure ?gateway",
+      "required": true
+    },
+    {
+      "signal": "http_403_block",
+      "source": "event_data",
+      "eventType": "diagnostics_upload_failed",
+      "dataField": "errorCode",
+      "operator": "contains",
+      "value": "403",
+      "required": false
+    }
+  ],
+  "confidenceFactors": [
+    {
+      "signal": "http_403_block",
+      "condition": "exists",
+      "weight": 15
+    }
+  ],
+  "confidenceThreshold": 70,
+  "explanation": "The agent collected a diagnostics package but the upload was answered with an **HTML block page from a web security gateway** instead of a response from the Autopilot Monitor backend — the event message names the product that served the page. A forward proxy / SWG with SSL inspection is intercepting HTTPS traffic from the enrollment network and blocking the upload endpoint.\n\nThe consequence is quietly painful: diagnostics upload is typically configured **OnFailure**, so the sessions that fail — the ones where the IME logs and diagnostics ZIP would explain the root cause — are exactly the sessions whose evidence never arrives. Enrollment telemetry itself may still flow (the agent often starts before the gateway's client enforcement does, or other endpoints are treated differently), which makes the gap easy to miss until a failure needs investigating.\n\nNote this rule only fires when the blocking page carries a recognizable security-product marker. A plain HTML error page without one usually means a stale or stopped endpoint instead — that is a different problem.",
+  "remediation": [
+    {
+      "title": "Exempt the upload endpoint in the web gateway",
+      "steps": [
+        "Identify the product from the block-page title quoted in this event's message (e.g. a Skyhigh/McAfee Web Gateway notification page)",
+        "In that gateway, add the Autopilot Monitor API host shown in the event message to the SSL-inspection bypass AND the URL allowlist for the enrollment network segment",
+        "Enrollment traffic often originates from a dedicated provisioning VLAN or from devices without the proxy client yet — make sure the exemption applies to that segment, not only to managed clients",
+        "If the gateway enforces per-user policy, remember ESP-phase traffic runs as SYSTEM/device before any user signs in — the exemption must cover unauthenticated device traffic"
+      ]
+    },
+    {
+      "title": "Verify the fix",
+      "steps": [
+        "Re-run an enrollment (or wait for the next failed one) and confirm a diagnostics package appears on the session in the portal",
+        "Optionally set diagnostics upload to Always temporarily to validate the path without needing a failure"
+      ]
+    }
+  ],
+  "relatedDocs": [
+    {
+      "title": "Microsoft Learn: Windows Autopilot networking requirements",
+      "url": "https://learn.microsoft.com/en-us/autopilot/networking-requirements"
+    }
+  ],
+  "tags": [
+    "network",
+    "proxy",
+    "ssl-inspection",
+    "swg",
+    "diagnostics"
+  ]
+}

rules/dist/analyze-rules.json

@@ -943,6 +943,97 @@
         "delivery-gap"
       ]
     },
+    {
+      "ruleId": "ANALYZE-APP-017",
+      "title": "App Install Blocked by Another Installer (0x80070652)",
+      "description": "Detects Win32 app installs that failed because the Windows Installer was busy with another installation (HRESULT 0x80070652 / MSI exit code 1618, ERROR_INSTALL_ALREADY_RUNNING). The IME retries on a fixed budget (~15-17 minutes across several attempts) and then reports the app as failed; when the app is ESP-blocking, the Device Setup Apps subcategory terminates with it.",
+      "severity": "high",
+      "category": "apps",
+      "version": "1.0.0",
+      "author": "Autopilot Monitor",
+      "enabled": true,
+      "baseConfidence": 70,
+      "conditions": [
+        {
+          "signal": "mutex_blocked_install",
+          "source": "event_type",
+          "eventType": "app_install_failed",
+          "dataField": "hresultFromWin32",
+          "operator": "equals",
+          "value": "-2147023278",
+          "required": true
+        },
+        {
+          "signal": "installer_exit_1618",
+          "source": "event_data",
+          "eventType": "app_install_failed",
+          "dataField": "exitCode",
+          "operator": "equals",
+          "value": "1618",
+          "required": false
+        },
+        {
+          "signal": "esp_failed_with_mutex_code",
+          "source": "event_data",
+          "eventType": "esp_failure_settle_started",
+          "dataField": "errorCode",
+          "operator": "equals",
+          "value": "0x80070652",
+          "required": false
+        }
+      ],
+      "confidenceFactors": [
+        {
+          "signal": "installer_exit_1618",
+          "condition": "exists",
+          "weight": 10
+        },
+        {
+          "signal": "esp_failed_with_mutex_code",
+          "condition": "exists",
+          "weight": 20
+        }
+      ],
+      "confidenceThreshold": 65,
+      "explanation": "App **{{appName}}** failed to install because the Windows Installer service was already busy with another installation — HRESULT **0x80070652** / MSI exit code **1618** (`ERROR_INSTALL_ALREADY_RUNNING`). Only one Windows Installer transaction can run at a time; the Intune Management Extension retried on its fixed budget (typically ~15-17 minutes across several attempts) and then reported the app as failed. If this app is required in the Enrollment Status Page, the Device Setup Apps subcategory fails with it and the enrollment terminates.\n\nThis failure is **deterministic per attempt**: as long as the competing installer keeps winning the race, a plain re-enrollment fails again at roughly the same minute mark — retrying without fixing the collision only churns devices.\n\nCommon sources of the competing installation:\n\n- The **preceding Win32 app in the install order**: its installer exits 0 (so IME moves on) but leaves a child `msiexec` transaction or post-install MSI work running. Security agents and proxy clients that chain multiple MSIs are frequent offenders.\n- **OEM factory software** installing on first boot (factory-image provisioning packages, vendor updaters) — typical on brand-new hardware batches.\n- **Microsoft 365 Apps (C2R), driver updaters or Windows servicing** running installations in parallel outside IME's control.",
+      "remediation": [
+        {
+          "title": "Identify the competing installer",
+          "steps": [
+            "In this session's timeline, note which app finished installing immediately before {{appName}} started — its installer is the prime suspect for holding the Windows Installer mutex",
+            "On a reproduction device, when the failure window is active, check for running installers: Get-Process msiexec | Select-Object Id,StartTime and the in-progress marker key HKLM\\SOFTWARE\\Microsoft\\Windows\\Installer\\InProgress",
+            "Check the Application event log for MsiInstaller events around the failure timestamp to see which product held the transaction",
+            "On factory-fresh hardware, also look for OEM first-boot installers (vendor updater services, factory provisioning packages) that run outside Intune"
+          ]
+        },
+        {
+          "title": "Serialize the install chain",
+          "steps": [
+            "Add an Intune Win32 dependency so {{appName}} depends on the app whose installer causes the collision — IME then orders them explicitly instead of racing",
+            "Alternatively, wrap the offending predecessor so its install script waits until msiexec has fully finished (poll the InProgress registry key or the _MSIExecute mutex with a bounded timeout) before exiting",
+            "If the app does not have to gate the ESP, remove it from the blocking-app list so a transient 1618 no longer terminates the enrollment; Intune retries it after the desktop"
+          ]
+        }
+      ],
+      "relatedDocs": [
+        {
+          "title": "Microsoft Learn: MsiExec.exe error messages (1618 = another installation is in progress)",
+          "url": "https://learn.microsoft.com/en-us/windows/win32/msi/error-codes"
+        },
+        {
+          "title": "Microsoft Learn: Troubleshoot Win32 app installations in Intune",
+          "url": "https://learn.microsoft.com/en-us/troubleshoot/mem/intune/app-management/troubleshoot-win32-app-install"
+        }
+      ],
+      "tags": [
+        "apps",
+        "msiexec",
+        "mutex",
+        "0x80070652",
+        "1618",
+        "esp"
+      ]
+    },
     {
       "ruleId": "ANALYZE-CORR-003",
       "title": "Proxy Configuration Causing Download Failure",
@@ -2964,6 +3055,86 @@
         "esp"
       ]
     },
+    {
+      "ruleId": "ANALYZE-NET-001",
+      "title": "Diagnostics Upload Blocked by Web Security Gateway",
+      "description": "Detects diagnostics package uploads that were answered by a security appliance's HTML block page instead of the Autopilot Monitor backend. A forward proxy / secure web gateway (SWG) with SSL inspection is intercepting the upload endpoint, so exactly the sessions where diagnostics matter most (OnFailure uploads) are the ones losing them.",
+      "severity": "warning",
+      "category": "network",
+      "version": "1.0.0",
+      "author": "Autopilot Monitor",
+      "enabled": true,
+      "baseConfidence": 75,
+      "conditions": [
+        {
+          "signal": "foreign_html_response",
+          "source": "event_data",
+          "eventType": "diagnostics_upload_failed",
+          "dataField": "errorCode",
+          "operator": "contains",
+          "value": "HTML platform error page",
+          "required": true
+        },
+        {
+          "signal": "security_gateway_marker",
+          "source": "event_data",
+          "eventType": "diagnostics_upload_failed",
+          "dataField": "errorCode",
+          "operator": "regex",
+          "value": "mcafee|skyhigh|zscaler|netskope|blue ?coat|proxysg|forcepoint|websense|palo ?alto|fortigate|fortiguard|sophos|watchguard|barracuda|iboss|umbrella|lightspeed|smoothwall|contentkeeper|web ?gateway|web ?filter|content ?filter|secure ?gateway",
+          "required": true
+        },
+        {
+          "signal": "http_403_block",
+          "source": "event_data",
+          "eventType": "diagnostics_upload_failed",
+          "dataField": "errorCode",
+          "operator": "contains",
+          "value": "403",
+          "required": false
+        }
+      ],
+      "confidenceFactors": [
+        {
+          "signal": "http_403_block",
+          "condition": "exists",
+          "weight": 15
+        }
+      ],
+      "confidenceThreshold": 70,
+      "explanation": "The agent collected a diagnostics package but the upload was answered with an **HTML block page from a web security gateway** instead of a response from the Autopilot Monitor backend — the event message names the product that served the page. A forward proxy / SWG with SSL inspection is intercepting HTTPS traffic from the enrollment network and blocking the upload endpoint.\n\nThe consequence is quietly painful: diagnostics upload is typically configured **OnFailure**, so the sessions that fail — the ones where the IME logs and diagnostics ZIP would explain the root cause — are exactly the sessions whose evidence never arrives. Enrollment telemetry itself may still flow (the agent often starts before the gateway's client enforcement does, or other endpoints are treated differently), which makes the gap easy to miss until a failure needs investigating.\n\nNote this rule only fires when the blocking page carries a recognizable security-product marker. A plain HTML error page without one usually means a stale or stopped endpoint instead — that is a different problem.",
+      "remediation": [
+        {
+          "title": "Exempt the upload endpoint in the web gateway",
+          "steps": [
+            "Identify the product from the block-page title quoted in this event's message (e.g. a Skyhigh/McAfee Web Gateway notification page)",
+            "In that gateway, add the Autopilot Monitor API host shown in the event message to the SSL-inspection bypass AND the URL allowlist for the enrollment network segment",
+            "Enrollment traffic often originates from a dedicated provisioning VLAN or from devices without the proxy client yet — make sure the exemption applies to that segment, not only to managed clients",
+            "If the gateway enforces per-user policy, remember ESP-phase traffic runs as SYSTEM/device before any user signs in — the exemption must cover unauthenticated device traffic"
+          ]
+        },
+        {
+          "title": "Verify the fix",
+          "steps": [
+            "Re-run an enrollment (or wait for the next failed one) and confirm a diagnostics package appears on the session in the portal",
+            "Optionally set diagnostics upload to Always temporarily to validate the path without needing a failure"
+          ]
+        }
+      ],
+      "relatedDocs": [
+        {
+          "title": "Microsoft Learn: Windows Autopilot networking requirements",
+          "url": "https://learn.microsoft.com/en-us/autopilot/networking-requirements"
+        }
+      ],
+      "tags": [
+        "network",
+        "proxy",
+        "ssl-inspection",
+        "swg",
+        "diagnostics"
+      ]
+    },
     {
       "ruleId": "ANALYZE-OFFICE-001",
       "title": "Microsoft 365 Apps Install Failed",

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Interop/WifiInfoProviderTests.cs

@@ -0,0 +1,140 @@
+#nullable enable
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Interop;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Interop
+{
+    /// <summary>
+    /// Tests for the tiered WiFi reader. The WLAN state of the test machine is unknown (CI
+    /// runners have no WLAN service, dev boxes may be on WiFi with or without location consent),
+    /// so the live path only pins the fail-soft contract. The diagnostics composer is pinned
+    /// exactly — it is the only field evidence for a missing wifi_signal_info event, and the
+    /// ERROR_ACCESS_DENIED hint is what tells an operator that Windows 11 24H2's location gate,
+    /// not the hardware, swallowed the SSID.
+    /// </summary>
+    public sealed class WifiInfoProviderTests
+    {
+        [Fact]
+        public void TryRead_never_throws_and_reports_a_reason_when_it_yields_nothing()
+        {
+            var result = WifiInfoProvider.TryRead(null, out var diagnostics);
+
+            if (result == null)
+            {
+                Assert.False(string.IsNullOrWhiteSpace(diagnostics),
+                    "a null result must always explain itself — that string is the only field evidence");
+                Assert.Contains("native:", diagnostics);
+                Assert.Contains("WinRT:", diagnostics);
+                Assert.Contains("netsh:", diagnostics);
+            }
+            else
+            {
+                Assert.Null(diagnostics);
+                // Every tier either carries an SSID or was not supposed to return at all.
+                Assert.False(result.Ssid == null && result.SignalPercent == null
+                             && result.RadioType == null && result.Channel == null,
+                    "an all-null payload must surface as null, not as an empty connection");
+            }
+        }
+
+        // ----- BuildDiagnostics ---------------------------------------------
+
+        [Fact]
+        public void BuildDiagnostics_names_every_tier()
+        {
+            var text = WifiInfoProvider.BuildDiagnostics(null, null);
+
+            Assert.Contains("no WiFi info from any reader", text);
+            Assert.Contains("native: no connected WLAN interface", text);
+            Assert.Contains("WinRT: no SSID", text);
+            Assert.Contains("netsh: no parsable output", text);
+        }
+
+        [Fact]
+        public void BuildDiagnostics_passes_through_tier_reasons()
+        {
+            var text = WifiInfoProvider.BuildDiagnostics("WlanOpenHandle rc=1062", "WinRT NetworkInformation unavailable");
+
+            Assert.Contains("native: WlanOpenHandle rc=1062", text);
+            Assert.Contains("WinRT: WinRT NetworkInformation unavailable", text);
+        }
+
+        [Fact]
+        public void BuildDiagnostics_explains_access_denied_as_the_location_gate()
+        {
+            var text = WifiInfoProvider.BuildDiagnostics(
+                "[1cbc79c3-2e31-468a-b949-17fafa6e23ed] query(current_connection) rc=5; ", null);
+
+            Assert.Contains("ERROR_ACCESS_DENIED", text);
+            Assert.Contains("24H2", text);
+            Assert.Contains("Location services", text);
+        }
+
+        [Fact]
+        public void BuildDiagnostics_explains_access_denied_without_a_trailing_separator()
+        {
+            var text = WifiInfoProvider.BuildDiagnostics("WlanOpenHandle rc=5", null);
+
+            Assert.Contains("ERROR_ACCESS_DENIED", text);
+        }
+
+        // ----- IsLocationGateDenied -----------------------------------------
+        //
+        // This predicate decides whether the wifi_signal_info payload claims
+        // "location_services_off" to the operator. A false positive blames a privacy setting
+        // that is actually fine, so the boundaries are pinned exactly.
+
+        [Theory]
+        [InlineData("[guid] query(current_connection) rc=5; ")]
+        [InlineData("WlanOpenHandle rc=5")]
+        public void IsLocationGateDenied_true_only_for_error_access_denied(string nativeDiag)
+        {
+            Assert.True(WifiInfoProvider.IsLocationGateDenied(nativeDiag));
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        [InlineData("query(current_connection) rc=50; ")]
+        [InlineData("query(current_connection) rc=5023; ")]
+        [InlineData("WlanEnumInterfaces rc=1062")]
+        [InlineData("no WLAN interfaces")]
+        [InlineData("[guid] state=wlan_interface_state_disconnected; ")]
+        public void IsLocationGateDenied_false_for_every_other_reason(string? nativeDiag)
+        {
+            Assert.False(WifiInfoProvider.IsLocationGateDenied(nativeDiag));
+        }
+
+        [Fact]
+        public void LocationServicesOff_literal_is_the_published_payload_contract()
+        {
+            // Matched verbatim by the portal's WiFi card (wifiDataLimitedReason) — renaming it
+            // silently drops the hint instead of breaking a build.
+            Assert.Equal("location_services_off", WifiInfoProvider.LocationServicesOff);
+        }
+
+        [Fact]
+        public void TryRead_never_claims_the_location_gate_on_the_native_tier()
+        {
+            // The native tier only returns when it succeeded, so a full payload must never carry
+            // a "data limited" reason.
+            var result = WifiInfoProvider.TryRead(null, out _);
+
+            if (result?.SignalPercent != null)
+                Assert.Null(result.DataLimitedReason);
+        }
+
+        [Theory]
+        [InlineData("query(current_connection) rc=50; ")]
+        [InlineData("query(current_connection) rc=5023; ")]
+        [InlineData("WlanEnumInterfaces rc=1062")]
+        [InlineData("[guid] state=wlan_interface_state_disconnected; ")]
+        public void BuildDiagnostics_does_not_blame_the_location_gate_for_other_codes(string nativeDiag)
+        {
+            var text = WifiInfoProvider.BuildDiagnostics(nativeDiag, null);
+
+            Assert.DoesNotContain("ERROR_ACCESS_DENIED", text);
+            Assert.Contains($"native: {nativeDiag}", text);
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Interop/WinRtWifiSsidReaderTests.cs

@@ -0,0 +1,48 @@
+#nullable enable
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Interop;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Interop
+{
+    /// <summary>
+    /// Tests for the WinRT SSID reader. Its whole value is that it keeps working where the
+    /// native WLAN API is denied, so the contract that matters here is fail-soft resolution:
+    /// the type is bound by name at runtime (no winmd), and every step must degrade to null
+    /// with a reason instead of throwing — a throw would take the Task.Run collector down
+    /// silently, which is precisely the failure mode this tier exists to end.
+    /// </summary>
+    public sealed class WinRtWifiSsidReaderTests
+    {
+        [Fact]
+        public void TryGetConnectedSsid_never_throws()
+        {
+            var ssid = WinRtWifiSsidReader.TryGetConnectedSsid(out var diagnostics);
+
+            if (ssid == null)
+                Assert.False(string.IsNullOrWhiteSpace(diagnostics), "a null SSID must carry a reason");
+            else
+                Assert.Null(diagnostics);
+        }
+
+        [Fact]
+        public void TryGetConnectedSsid_never_returns_an_empty_ssid()
+        {
+            // An AP broadcasting an empty SSID must surface as null, never as "" — the caller
+            // maps a non-null SSID straight into the wifi_signal_info payload.
+            var ssid = WinRtWifiSsidReader.TryGetConnectedSsid(out _);
+
+            Assert.True(ssid == null || ssid.Length > 0);
+        }
+
+        [Fact]
+        public void TryGetConnectedSsid_is_stable_across_calls()
+        {
+            // Reflection members are resolved once and cached; a second call must take the
+            // cached path and behave identically.
+            var first = WinRtWifiSsidReader.TryGetConnectedSsid(out _);
+            var second = WinRtWifiSsidReader.TryGetConnectedSsid(out _);
+
+            Assert.Equal(first, second);
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Runtime/DiagnosticsPackageServiceTests.cs

@@ -527,7 +527,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Runtime
         {
             // On-demand mid-session (no outcome yet): the OnFailure gate must NOT skip —
             // there is no known success to skip on. Reaching the archive build (sentinel
-            // throw → error result) proves the gate was passed; a skip would return null.
+            // throw → error result) proves the gate was passed; a skip would return Skipped.
             using var rig = new Rig();
             var result = await BuildGateProbe(rig.Logger, "OnFailure")
                 .CreateAndUploadAsync(enrollmentSucceeded: null, fileNameSuffix: "server-requested");
@@ -543,7 +543,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Runtime
             var result = await BuildGateProbe(rig.Logger, "OnFailure")
                 .CreateAndUploadAsync(enrollmentSucceeded: true);
 
-            Assert.Null(result);
+            Assert.NotNull(result);
+            Assert.True(result!.Skipped);
+            Assert.False(result.Success);
+            Assert.Equal(DiagnosticsUploadResult.SkipOnFailureSucceeded, result.ErrorCode);
         }
 
         [Fact]
@@ -553,7 +556,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Runtime
             var result = await BuildGateProbe(rig.Logger, "Off")
                 .CreateAndUploadAsync(enrollmentSucceeded: null);
 
-            Assert.Null(result);
+            // The gate name travels in ErrorCode so the dispatcher's server_action_failed
+            // event says "mode_off" instead of a generic "diagnostics_upload_failed".
+            Assert.NotNull(result);
+            Assert.True(result!.Skipped);
+            Assert.Equal(DiagnosticsUploadResult.SkipModeOff, result.ErrorCode);
         }
 
         [Theory]

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Runtime/ServerActionDispatcherTests.cs

@@ -122,6 +122,28 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Runtime
             Assert.Equal("config_fetch_failed", (string)typed["failureReason"]);
         }
 
+        [Fact]
+        public async Task Dispatch_request_diagnostics_skipped_by_gate_surfaces_gate_name_as_failure_reason()
+        {
+            // Session 2550bcea (2026-08-29): the on-demand collection was refused by the
+            // mode=Off gate and the portal only saw a generic "diagnostics_upload_failed".
+            // The gate name must travel through to the event so the operator can tell a
+            // config gate from a real upload error.
+            using var rig = new Rig();
+            rig.DiagnosticsResult = DiagnosticsUploadResult.SkippedBy(DiagnosticsUploadResult.SkipModeOff);
+
+            await rig.Build().DispatchAsync(new List<ServerAction>
+            {
+                new ServerAction { Type = ServerActionTypes.RequestDiagnostics, QueuedAt = DateTime.UtcNow },
+            });
+
+            Assert.Equal(1, rig.DiagnosticsCalls);
+            Assert.Empty(rig.EventsOfType("server_action_executed"));
+            var failed = rig.EventsOfType("server_action_failed").Single();
+            var typed = Assert.IsAssignableFrom<IReadOnlyDictionary<string, object>>(failed.TypedPayload!);
+            Assert.Equal(DiagnosticsUploadResult.SkipModeOff, (string)typed["failureReason"]);
+        }
+
         [Fact]
         public async Task Dispatch_unknown_action_type_emits_failed_with_unknown_action_type_reason()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Orchestration/SignalIngressTests.cs

@@ -498,6 +498,207 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Orchestration
             Assert.Equal(5, observedCount);
         }
 
+        // ============================================================ Worker re-entrancy (2026-08-29)
+
+        [Fact]
+        public void Worker_thread_post_with_full_channel_does_not_deadlock_and_is_processed_next()
+        {
+            // Channel capacity 1, the worker is parked inside ApplyStep on a gate while a
+            // second producer keeps the channel full. When the gate opens, ApplyStep posts a
+            // verdict from the worker thread. Before the fix, Post would block in
+            // BlockingCollection.Add forever (the worker is the only consumer). After the fix,
+            // the verdict goes to the worker-local queue, is processed BEFORE the queued channel
+            // item, and the worker keeps draining.
+            using var tmp = new TempDirectory();
+            var log = new SignalLogWriter(tmp.File("signal-log.jsonl"));
+            SignalIngress? ingRef = null;
+            var gate = new ManualResetEventSlim(false);
+            var inApply = new ManualResetEventSlim(false);
+            var processor = new GatedReentrantProcessor(() => ingRef!, gate, inApply);
+            var ing = new SignalIngress(
+                engine: new DecisionEngine(),
+                signalLog: log,
+                traceCounter: new SessionTraceOrdinalProvider(),
+                processor: processor,
+                clock: new VirtualClock(At),
+                channelCapacity: 1);
+            ingRef = ing;
+            ing.Start();
+
+            // Item 0 — worker takes it and parks inside ApplyStep on the gate.
+            ing.Post(DecisionSignalKind.SessionStarted, At, "Collector", RawEvidence("s0"));
+            Assert.True(inApply.Wait(5000));
+
+            // Item 1 fills the single slot; item 2 blocks a foreign producer (channel full).
+            ing.Post(DecisionSignalKind.DesktopArrived, At.AddSeconds(1), "Collector", RawEvidence("s1"));
+            var blockedProducer = Task.Run(() =>
+                ing.Post(DecisionSignalKind.DesktopArrived, At.AddSeconds(2), "Collector", RawEvidence("s2")));
+            Assert.True(WaitFor(() => ing.ApproximateQueueLength == 1));
+            Assert.False(blockedProducer.Wait(200));   // genuinely blocked by back-pressure
+
+            // Release the worker: ApplyStep(s0) now posts the verdict from the worker thread
+            // into a full channel.
+            gate.Set();
+
+            Assert.True(blockedProducer.Wait(5000), "foreign producer must be released — worker must keep draining");
+            Assert.True(WaitFor(() => processor.CallCount == 4));
+            ing.Stop();
+
+            Assert.Equal(
+                new[]
+                {
+                    DecisionSignalKind.SessionStarted,
+                    DecisionSignalKind.ClassifierVerdictIssued,   // follow-up drained BEFORE the next channel item
+                    DecisionSignalKind.DesktopArrived,
+                    DecisionSignalKind.DesktopArrived,
+                },
+                processor.Kinds);
+            Assert.Equal(1, ing.ReentrantPostCount);
+            Assert.Equal(0, ing.PendingSignalCount);
+            // Same worker thread for every step — single-writer invariant intact.
+            Assert.Single(processor.ThreadIds.Distinct());
+            // Follow-up went through the normal path: ordinal assigned + durably logged.
+            var logged = log.ReadAll();
+            Assert.Equal(4, logged.Count);
+            Assert.Equal(DecisionSignalKind.ClassifierVerdictIssued, logged[1].Kind);
+            Assert.Equal(1, logged[1].SessionSignalOrdinal);
+        }
+
+        [Fact]
+        public void Worker_thread_post_chain_is_drained_iteratively_in_order()
+        {
+            // A follow-up whose own ApplyStep posts another follow-up: both are processed on
+            // the worker, in order, before the next channel item, without recursion.
+            using var tmp = new TempDirectory();
+            var log = new SignalLogWriter(tmp.File("signal-log.jsonl"));
+            SignalIngress? ingRef = null;
+            var processor = new ChainingProcessor(() => ingRef!);
+            var ing = new SignalIngress(
+                engine: new DecisionEngine(),
+                signalLog: log,
+                traceCounter: new SessionTraceOrdinalProvider(),
+                processor: processor,
+                clock: new VirtualClock(At));
+            ingRef = ing;
+            ing.Start();
+
+            ing.Post(DecisionSignalKind.SessionStarted, At, "Collector", RawEvidence("s0"));
+            ing.Post(DecisionSignalKind.DesktopArrived, At.AddSeconds(1), "Collector", RawEvidence("s1"));
+            ing.Stop();
+
+            Assert.Equal(
+                new[] { "Collector", "chain:1", "chain:2", "Collector" },
+                processor.Origins);
+            Assert.Equal(2, ing.ReentrantPostCount);
+            Assert.Equal(4, log.ReadAll().Count);
+        }
+
+        [Fact]
+        public void Worker_thread_post_during_Stop_drain_is_still_processed()
+        {
+            // Stop() completes adding, but a verdict posted by the worker while it finishes
+            // the last channel item must not be dropped — it belongs to that step.
+            using var tmp = new TempDirectory();
+            var log = new SignalLogWriter(tmp.File("signal-log.jsonl"));
+            SignalIngress? ingRef = null;
+            var gate = new ManualResetEventSlim(false);
+            var inApply = new ManualResetEventSlim(false);
+            var processor = new GatedReentrantProcessor(() => ingRef!, gate, inApply);
+            var ing = new SignalIngress(
+                engine: new DecisionEngine(),
+                signalLog: log,
+                traceCounter: new SessionTraceOrdinalProvider(),
+                processor: processor,
+                clock: new VirtualClock(At));
+            ingRef = ing;
+            ing.Start();
+
+            ing.Post(DecisionSignalKind.SessionStarted, At, "Collector", RawEvidence("s0"));
+            Assert.True(inApply.Wait(5000));
+            var stopTask = Task.Run(() => ing.Stop());
+            Assert.True(WaitFor(() => ing.ApproximateQueueLength == 0 && !stopTask.IsCompleted));
+            gate.Set();
+            Assert.True(stopTask.Wait(5000));
+
+            Assert.Equal(
+                new[] { DecisionSignalKind.SessionStarted, DecisionSignalKind.ClassifierVerdictIssued },
+                processor.Kinds);
+            Assert.Equal(2, log.ReadAll().Count);
+        }
+
+        /// <summary>
+        /// Parks inside ApplyStep(SessionStarted) on a gate, then posts a verdict back into the
+        /// ingress from the worker thread — the EffectRunner/RunClassifier shape.
+        /// </summary>
+        private sealed class GatedReentrantProcessor : IDecisionStepProcessor
+        {
+            private readonly Func<ISignalIngressSink> _sink;
+            private readonly ManualResetEventSlim _gate;
+            private readonly ManualResetEventSlim _inApply;
+            private readonly List<(DecisionSignalKind Kind, int ThreadId)> _calls = new List<(DecisionSignalKind, int)>();
+            private DecisionCore.State.DecisionState _state = DecisionCore.State.DecisionState.CreateInitial("S1", "T1");
+
+            public GatedReentrantProcessor(Func<ISignalIngressSink> sink, ManualResetEventSlim gate, ManualResetEventSlim inApply)
+            {
+                _sink = sink;
+                _gate = gate;
+                _inApply = inApply;
+            }
+
+            public int CallCount { get { lock (_calls) { return _calls.Count; } } }
+            public DecisionSignalKind[] Kinds { get { lock (_calls) { return _calls.Select(c => c.Kind).ToArray(); } } }
+            public int[] ThreadIds { get { lock (_calls) { return _calls.Select(c => c.ThreadId).ToArray(); } } }
+
+            public DecisionCore.State.DecisionState CurrentState => _state;
+
+            public EffectRunResult ApplyStep(DecisionStep step, DecisionSignal signal)
+            {
+                lock (_calls) { _calls.Add((signal.Kind, Thread.CurrentThread.ManagedThreadId)); }
+                _state = step.NewState;
+                if (signal.Kind == DecisionSignalKind.SessionStarted)
+                {
+                    _inApply.Set();
+                    _gate.Wait();
+                    _sink().Post(
+                        DecisionSignalKind.ClassifierVerdictIssued,
+                        signal.OccurredAtUtc,
+                        "effectrunner:classifier:test",
+                        new Evidence(EvidenceKind.Synthetic, "classifier:test:h", "Strong/90"),
+                        new Dictionary<string, string> { ["level"] = "Strong" });
+                }
+                return EffectRunResult.Empty();
+            }
+        }
+
+        private sealed class ChainingProcessor : IDecisionStepProcessor
+        {
+            private readonly Func<ISignalIngressSink> _sink;
+            private DecisionCore.State.DecisionState _state = DecisionCore.State.DecisionState.CreateInitial("S1", "T1");
+            public List<string> Origins { get; } = new List<string>();
+
+            public ChainingProcessor(Func<ISignalIngressSink> sink) { _sink = sink; }
+
+            public DecisionCore.State.DecisionState CurrentState => _state;
+
+            public EffectRunResult ApplyStep(DecisionStep step, DecisionSignal signal)
+            {
+                Origins.Add(signal.SourceOrigin);
+                _state = step.NewState;
+                string? next = signal.Kind == DecisionSignalKind.SessionStarted ? "chain:1"
+                    : signal.SourceOrigin == "chain:1" ? "chain:2"
+                    : null;
+                if (next != null)
+                {
+                    _sink().Post(
+                        DecisionSignalKind.ClassifierVerdictIssued,
+                        signal.OccurredAtUtc,
+                        next,
+                        new Evidence(EvidenceKind.Synthetic, next, next));
+                }
+                return EffectRunResult.Empty();
+            }
+        }
+
         [Fact]
         public void Post_via_ISignalIngressSink_reaches_reducer_like_any_signal()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Program/BackendSessionRegistrationTests.cs

@@ -58,6 +58,47 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Program
             Assert.Same(registration, result.Registration);
         }
 
+        [Fact]
+        public void RotateSession_rotates_id_updates_config_drops_spool_and_keeps_whiteglove_marker()
+        {
+            using var tmp = new TempDirectory();
+            var logger = NewLogger(tmp.Path);
+            var persistence = new SessionIdPersistence(tmp.Path);
+            var original = persistence.GetOrCreate();
+            persistence.SaveWhiteGloveComplete();
+            var config = new AgentConfiguration { ApiBaseUrl = "https://example.invalid", TenantId = "t", SessionId = original };
+
+            var transportDir = Path.Combine(tmp.Path, "Spool");
+            Directory.CreateDirectory(transportDir);
+            File.WriteAllText(Path.Combine(transportDir, "spool.jsonl"), "{}");
+            File.WriteAllText(Path.Combine(transportDir, "upload-cursor.json"), "{}");
+            File.WriteAllText(Path.Combine(transportDir, "unrelated.txt"), "keep");
+
+            var rotated = BackendSessionRegistration.RotateSession(config, persistence, auth: null, transportDir, logger);
+
+            Assert.NotEqual(original, rotated);
+            Assert.Equal(rotated, config.SessionId);
+            Assert.Equal(rotated, new SessionIdPersistence(tmp.Path).GetOrCreate());
+            Assert.True(persistence.IsWhiteGloveResume());
+            Assert.False(File.Exists(Path.Combine(transportDir, "spool.jsonl")));
+            Assert.False(File.Exists(Path.Combine(transportDir, "upload-cursor.json")));
+            Assert.True(File.Exists(Path.Combine(transportDir, "unrelated.txt")));
+        }
+
+        [Fact]
+        public void RotateSession_tolerates_a_missing_transport_directory()
+        {
+            using var tmp = new TempDirectory();
+            var logger = NewLogger(tmp.Path);
+            var persistence = new SessionIdPersistence(tmp.Path);
+            var config = new AgentConfiguration { ApiBaseUrl = "https://example.invalid", TenantId = "t", SessionId = persistence.GetOrCreate() };
+
+            var rotated = BackendSessionRegistration.RotateSession(
+                config, persistence, auth: null, Path.Combine(tmp.Path, "does-not-exist"), logger);
+
+            Assert.Equal(rotated, config.SessionId);
+        }
+
         [Fact]
         public void Register_throws_on_null_arguments()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Security/SessionIdPersistenceTests.cs

@@ -72,6 +72,26 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Security
             Assert.NotEqual(first, second);
         }
 
+        [Fact]
+        public void Rotate_writes_a_new_id_and_keeps_the_whiteglove_marker()
+        {
+            using var tmp = new TempDirectory();
+            var sut = new SessionIdPersistence(tmp.Path);
+            var first = sut.GetOrCreate();
+            sut.SaveWhiteGloveComplete();
+            var createdBefore = File.ReadAllText(Path.Combine(tmp.Path, "session.created"));
+
+            var rotated = sut.Rotate();
+
+            Assert.True(Guid.TryParse(rotated, out _));
+            Assert.NotEqual(first, rotated);
+            Assert.Equal(rotated, File.ReadAllText(Path.Combine(tmp.Path, "session.id")));
+            Assert.Equal(rotated, new SessionIdPersistence(tmp.Path).GetOrCreate());
+            Assert.True(sut.IsWhiteGloveResume(), "Rotate must not clear whiteglove.complete (unlike Delete)");
+            Assert.True(File.Exists(Path.Combine(tmp.Path, "session.created")));
+            Assert.NotEqual(createdBefore, File.ReadAllText(Path.Combine(tmp.Path, "session.created")));
+        }
+
         [Fact]
         public void Ctor_creates_data_directory_when_missing()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Security/SessionRegistrationHelperTests.cs

@@ -96,6 +96,112 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Security
             Assert.Equal(1, tracker.ConsecutiveFailures);
         }
 
+        // ── SESSION-OWNER-BINDING ────────────────────────────────────────────
+
+        private static BackendAuthException OwnerMismatch()
+            => new BackendAuthException("Backend returned 403 Forbidden.", statusCode: 403,
+                errorCode: AutopilotMonitor.Shared.Constants.AgentErrorCodes.SessionOwnerMismatch);
+
+        [Fact]
+        public async Task Owner_mismatch_rotates_once_and_re_registers_without_recording_an_auth_failure()
+        {
+            using var tmp = new TempDirectory();
+            var logger = NewLogger(tmp);
+            var config = NewConfig();
+            var originalSessionId = config.SessionId;
+            var rotatedTo = Guid.NewGuid().ToString();
+            var seenSessionIds = new System.Collections.Generic.List<string>();
+
+            var apiClient = new FakeApiClient(
+                attempt => attempt == 1
+                    ? throw OwnerMismatch()
+                    : new RegisterSessionResponse { Success = true, SessionId = rotatedTo, ValidatedBy = ValidatorType.AutopilotV1 },
+                onRegister: r => seenSessionIds.Add(r.SessionId));
+
+            var tracker = new AuthFailureTracker(maxFailures: 5, timeoutMinutes: 0,
+                clock: SystemClock.Instance, logger: logger);
+            var rotations = 0;
+
+            var result = await SessionRegistrationHelper.RegisterWithRetryAsync(
+                apiClient, config, agentVersion: "0.0.0", logger: logger,
+                authFailureTracker: tracker,
+                backoffDelay: _ => throw new InvalidOperationException("rotation must retry without backoff"),
+                networkLinkWait: _ => Task.CompletedTask,
+                rotateSession: () => { rotations++; config.SessionId = rotatedTo; return rotatedTo; });
+
+            Assert.Equal(SessionRegistrationOutcome.Succeeded, result.Outcome);
+            Assert.Equal(2, apiClient.CallCount);
+            Assert.Equal(1, rotations);
+            Assert.Equal(0, tracker.ConsecutiveFailures);
+            Assert.Equal(new[] { originalSessionId, rotatedTo }, seenSessionIds);
+            Assert.Equal(originalSessionId, result.RotatedFromSessionId);
+        }
+
+        [Fact]
+        public async Task Second_owner_mismatch_after_rotation_is_an_auth_failure()
+        {
+            using var tmp = new TempDirectory();
+            var logger = NewLogger(tmp);
+            var config = NewConfig();
+
+            var apiClient = new FakeApiClient(_ => throw OwnerMismatch());
+            var tracker = new AuthFailureTracker(maxFailures: 5, timeoutMinutes: 0,
+                clock: SystemClock.Instance, logger: logger);
+
+            var result = await SessionRegistrationHelper.RegisterWithRetryAsync(
+                apiClient, config, agentVersion: "0.0.0", logger: logger,
+                authFailureTracker: tracker,
+                networkLinkWait: _ => Task.CompletedTask,
+                rotateSession: () => { config.SessionId = Guid.NewGuid().ToString(); return config.SessionId; });
+
+            Assert.Equal(SessionRegistrationOutcome.AuthFailed, result.Outcome);
+            Assert.Equal(403, result.HttpStatusCode);
+            Assert.Equal(2, apiClient.CallCount);
+            Assert.Equal(1, tracker.ConsecutiveFailures);
+        }
+
+        [Fact]
+        public async Task Owner_mismatch_without_rotation_hook_behaves_like_any_auth_failure()
+        {
+            using var tmp = new TempDirectory();
+            var logger = NewLogger(tmp);
+            var config = NewConfig();
+
+            var apiClient = new FakeApiClient(_ => throw OwnerMismatch());
+            var tracker = new AuthFailureTracker(maxFailures: 5, timeoutMinutes: 0,
+                clock: SystemClock.Instance, logger: logger);
+
+            var result = await SessionRegistrationHelper.RegisterWithRetryAsync(
+                apiClient, config, agentVersion: "0.0.0", logger: logger,
+                authFailureTracker: tracker, networkLinkWait: _ => Task.CompletedTask);
+
+            Assert.Equal(SessionRegistrationOutcome.AuthFailed, result.Outcome);
+            Assert.Equal(1, apiClient.CallCount);
+            Assert.Equal(1, tracker.ConsecutiveFailures);
+            Assert.Null(result.RotatedFromSessionId);
+        }
+
+        [Fact]
+        public async Task Rotation_hook_failure_falls_back_to_auth_failed()
+        {
+            using var tmp = new TempDirectory();
+            var logger = NewLogger(tmp);
+            var config = NewConfig();
+
+            var apiClient = new FakeApiClient(_ => throw OwnerMismatch());
+            var tracker = new AuthFailureTracker(maxFailures: 5, timeoutMinutes: 0,
+                clock: SystemClock.Instance, logger: logger);
+
+            var result = await SessionRegistrationHelper.RegisterWithRetryAsync(
+                apiClient, config, agentVersion: "0.0.0", logger: logger,
+                authFailureTracker: tracker, networkLinkWait: _ => Task.CompletedTask,
+                rotateSession: () => throw new IOException("disk full"));
+
+            Assert.Equal(SessionRegistrationOutcome.AuthFailed, result.Outcome);
+            Assert.Equal(1, apiClient.CallCount);
+            Assert.Equal(1, tracker.ConsecutiveFailures);
+        }
+
         [Fact]
         public async Task Fails_after_six_exceptions_without_auth_error()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Transport/BackendApiClientAuthClassificationTests.cs

@@ -61,6 +61,46 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Transport
             Assert.Contains("The device is not authorized", ex.Message);
         }
 
+        [Fact]
+        public async Task Backend_json_403_carries_the_errorCode_when_present()
+        {
+            using var client = BuildClient(
+                HttpStatusCode.Forbidden,
+                "{\"success\":false,\"message\":\"Session belongs to another device\",\"errorCode\":\"session_owner_mismatch\"}",
+                "application/json");
+
+            var ex = await Assert.ThrowsAsync<BackendAuthException>(() => client.GetAgentConfigAsync("tenant-1"));
+
+            Assert.Equal(403, ex.StatusCode);
+            Assert.False(ex.EndpointUnavailable);
+            Assert.Equal("session_owner_mismatch", ex.ErrorCode);
+        }
+
+        [Fact]
+        public async Task Backend_json_403_without_errorCode_yields_null()
+        {
+            using var client = BuildClient(
+                HttpStatusCode.Forbidden,
+                "{\"success\":false,\"message\":\"Device validation failed\"}",
+                "application/json");
+
+            var ex = await Assert.ThrowsAsync<BackendAuthException>(() => client.GetAgentConfigAsync("tenant-1"));
+            Assert.Null(ex.ErrorCode);
+        }
+
+        [Theory]
+        [InlineData(null, null)]
+        [InlineData("", null)]
+        [InlineData("not json", null)]
+        [InlineData("<html><body>403</body></html>", null)]
+        [InlineData("{\"errorCode\":42}", null)]
+        [InlineData("{\"errorCode\":\"  \"}", null)]
+        [InlineData("{\"errorCode\":\"session_owner_mismatch\"}", "session_owner_mismatch")]
+        [InlineData("{\"ErrorCode\":\"session_owner_mismatch\"}", "session_owner_mismatch")]
+        [InlineData("  {\"success\":false,\"errorCode\":\" x \"}", "x")]
+        public void TryExtractErrorCode_is_tolerant(string? body, string? expected)
+            => Assert.Equal(expected, BackendApiClient.TryExtractErrorCode(body!));
+
         [Fact]
         public async Task Platform_html_403_is_reported_as_endpoint_unavailable_with_page_title()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/WifiInfoProvider.cs

@@ -0,0 +1,106 @@
+using System;
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Interop
+{
+    /// <summary>
+    /// The single entry point every collector uses to read the current WiFi connection. Owns the
+    /// tier order so the two callers (<c>DeviceInfoCollector</c>, <c>NetworkChangeDetector</c>)
+    /// cannot drift apart:
+    /// <list type="number">
+    /// <item><see cref="WifiInfoReader"/> — native WLAN API. Full payload (SSID, signal, PHY,
+    /// channel), but Windows 11 24H2+ requires precise-location consent for it.</item>
+    /// <item><see cref="WinRtWifiSsidReader"/> — WinRT <c>GetConnectedSsid</c>. SSID only, but
+    /// NOT location-gated; this is the tier that carries 24H2+ devices whose image has location
+    /// services off (the common OOBE case — see that class for the mechanism).</item>
+    /// <item><see cref="NetshWifiFallback"/> — process spawn, localized output parsing. Last
+    /// resort: it hangs off the same location gate as tier 1, so it only helps when the native
+    /// API failed for an unrelated reason.</item>
+    /// </list>
+    /// Never throws. Returns null when the device has no readable WiFi connection.
+    /// </summary>
+    internal static class WifiInfoProvider
+    {
+        /// <summary>
+        /// <see cref="WifiConnectionInfo.DataLimitedReason"/> value for a payload cut down to the
+        /// SSID by the Windows 11 24H2 location gate. Travels verbatim into the
+        /// <c>wifi_signal_info</c> payload as <c>wifiDataLimitedReason</c> and is matched by the
+        /// portal's WiFi card — a published contract, so do not rename it.
+        /// </summary>
+        internal const string LocationServicesOff = "location_services_off";
+
+        /// <summary>
+        /// True when the native tier reported <c>ERROR_ACCESS_DENIED</c> — "rc=5" but not
+        /// "rc=50"/"rc=5023"; the diagnostics string ends the code with ';' or end-of-line.
+        /// That is the 24H2 location gate, not a driver or hardware fault.
+        /// Internal for direct unit-testing via InternalsVisibleTo.
+        /// </summary>
+        internal static bool IsLocationGateDenied(string nativeDiag)
+            => !string.IsNullOrEmpty(nativeDiag) && Regex.IsMatch(nativeDiag, @"rc=5(?!\d)");
+
+        /// <summary>
+        /// Reads the current WiFi connection, walking the tiers until one yields something.
+        /// <paramref name="preferredInterfaceId"/> is the adapter GUID from
+        /// <c>NetworkInterface.Id</c> (tier 1 only). <paramref name="diagnostics"/> is null on
+        /// success and otherwise explains what every tier reported — log it at Warning: this is
+        /// the only field evidence for a missing <c>wifi_signal_info</c> event.
+        /// </summary>
+        internal static WifiConnectionInfo TryRead(Guid? preferredInterfaceId, out string diagnostics)
+        {
+            var native = WifiInfoReader.TryGetCurrentConnection(preferredInterfaceId, out var nativeDiag);
+            if (native != null)
+            {
+                diagnostics = null;
+                return native;
+            }
+
+            var ssid = WinRtWifiSsidReader.TryGetConnectedSsid(out var winRtDiag);
+            if (ssid != null)
+            {
+                diagnostics = null;
+                return new WifiConnectionInfo
+                {
+                    Ssid = ssid,
+                    // Only claim the location gate when the native tier actually said so. Any
+                    // other native failure (no WLAN service, no connected interface) leaves this
+                    // null rather than blaming a setting we did not observe.
+                    DataLimitedReason = IsLocationGateDenied(nativeDiag) ? LocationServicesOff : null,
+                };
+            }
+
+            var netsh = NetshWifiFallback.TryRead();
+            if (netsh != null)
+            {
+                diagnostics = null;
+                return netsh;
+            }
+
+            diagnostics = BuildDiagnostics(nativeDiag, winRtDiag);
+            return null;
+        }
+
+        /// <summary>
+        /// Composes the all-tiers-failed message. A native <c>rc=5</c> (ERROR_ACCESS_DENIED) is
+        /// spelled out: that is the 24H2 location gate, not a driver or hardware fault, and it
+        /// takes the netsh tier down with it — without this hint the log reads like a mystery.
+        /// Internal for direct unit-testing via InternalsVisibleTo.
+        /// </summary>
+        internal static string BuildDiagnostics(string nativeDiag, string winRtDiag)
+        {
+            var text = new StringBuilder("no WiFi info from any reader");
+            text.Append(" — native: ").Append(string.IsNullOrEmpty(nativeDiag) ? "no connected WLAN interface" : nativeDiag);
+            text.Append("; WinRT: ").Append(string.IsNullOrEmpty(winRtDiag) ? "no SSID" : winRtDiag);
+            text.Append("; netsh: no parsable output");
+
+            if (IsLocationGateDenied(nativeDiag))
+            {
+                text.Append(". rc=5 is ERROR_ACCESS_DENIED — Windows 11 24H2+ gates the current-connection "
+                          + "opcode (and netsh wlan) behind precise-location consent, which is off in this image; "
+                          + "enable Location services to restore signal/PHY/channel.");
+            }
+
+            return text.ToString();
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/WifiInfoReader.cs

@@ -15,7 +15,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Interop
 
         /// <summary>
         /// Signal quality 0–100 (same semantics as the netsh "Signal" percentage). Always set
-        /// on the native WLAN API path; null only when the netsh fallback could not parse it.
+        /// on the native WLAN API path; null when the netsh fallback could not parse it, and
+        /// always null on the WinRT tier (<see cref="WinRtWifiSsidReader"/> yields SSID only).
         /// </summary>
         public int? SignalPercent { get; internal set; }
 
@@ -24,6 +25,14 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Interop
 
         /// <summary>Current 802.11 channel number; null when the channel query fails.</summary>
         public int? Channel { get; internal set; }
+
+        /// <summary>
+        /// Why the payload is incomplete, when that is known — currently only
+        /// <c>location_services_off</c>: the SSID came from the ungated WinRT tier because the
+        /// native API was denied by the Windows 11 24H2 location gate, so signal, PHY and
+        /// channel have no source. Null whenever the reason is unknown; never a guess.
+        /// </summary>
+        public string DataLimitedReason { get; internal set; }
     }
 
     /// <summary>

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Interop/WinRtWifiSsidReader.cs

@@ -0,0 +1,146 @@
+using System;
+using System.Collections;
+using System.Reflection;
+
+namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Interop
+{
+    /// <summary>
+    /// Reads the SSID of the current WLAN connection via WinRT
+    /// <c>Windows.Networking.Connectivity.WlanConnectionProfileDetails.GetConnectedSsid</c>.
+    /// <para>
+    /// <b>Why this exists.</b> Windows 11 24H2 put the native WLAN API behind precise-location
+    /// consent: <c>WlanQueryInterface</c> with <c>wlan_intf_opcode_current_connection</c> — the
+    /// exact opcode <see cref="WifiInfoReader"/> needs — returns <c>ERROR_ACCESS_DENIED</c>
+    /// without it, and <c>netsh wlan</c> is gated by the same rule, so
+    /// <see cref="NetshWifiFallback"/> fails in lockstep. The consent prompt only appears for
+    /// processes in the user's context outside <c>C:\Windows\System32</c>, so the agent — SYSTEM,
+    /// during OOBE, before the user ever sees the privacy page — is denied silently. Microsoft
+    /// names <c>GetConnectedSsid</c> as the replacement for exactly this case; it is not
+    /// location-gated.
+    /// </para>
+    /// <para>
+    /// Resolved through the CLR's built-in WinRT projection — no NuGet package, no winmd
+    /// reference — the same mechanism <see cref="OobeStateReader"/> uses (validated from the
+    /// SYSTEM service context). Available since Windows 10 1507. SSID only: signal quality,
+    /// PHY type and channel have no ungated source, so they stay null on this path.
+    /// </para>
+    /// </summary>
+    internal static class WinRtWifiSsidReader
+    {
+        // Resolved once per process. Benign race: concurrent first calls resolve the same
+        // members and the assignments are idempotent — no lock needed.
+        private static MethodInfo _getInternetConnectionProfile;
+        private static MethodInfo _getConnectionProfiles;
+        private static bool _initTried;
+
+        /// <summary>
+        /// Returns the SSID of the connected WLAN, or null when the device is not on WiFi, the
+        /// WinRT contract is unavailable, or any part of the read fails. Never throws.
+        /// <paramref name="diagnostics"/> carries the reason when the result is null.
+        /// </summary>
+        internal static string TryGetConnectedSsid(out string diagnostics)
+        {
+            try
+            {
+                EnsureInitialized();
+
+                if (_getInternetConnectionProfile == null)
+                {
+                    diagnostics = "WinRT NetworkInformation unavailable";
+                    return null;
+                }
+
+                // The internet-bearing profile is the one the device is actually enrolling over.
+                var ssid = ReadSsid(_getInternetConnectionProfile.Invoke(null, null));
+                if (ssid != null)
+                {
+                    diagnostics = null;
+                    return ssid;
+                }
+
+                // No internet profile (captive portal, limited connectivity) or it is not WLAN —
+                // fall back to the first connected profile that carries WLAN details.
+                ssid = ScanConnectionProfiles();
+                diagnostics = ssid == null ? "no connected WLAN profile" : null;
+                return ssid;
+            }
+            catch (Exception ex)
+            {
+                diagnostics = $"WinRT exception {ex.GetType().Name}: {ex.Message}";
+                return null;
+            }
+        }
+
+        private static void EnsureInitialized()
+        {
+            if (_initTried) return;
+
+            var type = Type.GetType(
+                "Windows.Networking.Connectivity.NetworkInformation, Windows.Networking.Connectivity, ContentType=WindowsRuntime",
+                throwOnError: false);
+
+            _getInternetConnectionProfile = type?.GetMethod(
+                "GetInternetConnectionProfile", BindingFlags.Public | BindingFlags.Static, null, Type.EmptyTypes, null);
+            _getConnectionProfiles = type?.GetMethod(
+                "GetConnectionProfiles", BindingFlags.Public | BindingFlags.Static, null, Type.EmptyTypes, null);
+
+            _initTried = true;
+        }
+
+        /// <summary>
+        /// Walks every known connection profile and returns the SSID of the first one that is
+        /// both connected and WLAN. Returns null when none qualifies.
+        /// </summary>
+        private static string ScanConnectionProfiles()
+        {
+            if (_getConnectionProfiles == null)
+                return null;
+
+            if (!(_getConnectionProfiles.Invoke(null, null) is IEnumerable profiles))
+                return null;
+
+            foreach (var profile in profiles)
+            {
+                if (!IsConnected(profile))
+                    continue;
+
+                var ssid = ReadSsid(profile);
+                if (ssid != null)
+                    return ssid;
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// <c>ConnectionProfile.GetNetworkConnectivityLevel() != NetworkConnectivityLevel.None</c>.
+        /// A profile the device is not currently on would otherwise leak a stale SSID.
+        /// Unreadable level counts as not connected.
+        /// </summary>
+        private static bool IsConnected(object profile)
+        {
+            var level = profile?.GetType()
+                .GetMethod("GetNetworkConnectivityLevel", BindingFlags.Public | BindingFlags.Instance, null, Type.EmptyTypes, null)
+                ?.Invoke(profile, null);
+
+            return level != null && Convert.ToInt32(level) != 0; // NetworkConnectivityLevel.None
+        }
+
+        /// <summary>
+        /// <c>ConnectionProfile.WlanConnectionProfileDetails.GetConnectedSsid()</c>, or null when
+        /// the profile is not a WLAN profile or the SSID is empty (hidden network).
+        /// </summary>
+        private static string ReadSsid(object profile)
+        {
+            var details = profile?.GetType()
+                .GetProperty("WlanConnectionProfileDetails", BindingFlags.Public | BindingFlags.Instance)
+                ?.GetValue(profile);
+
+            var ssid = details?.GetType()
+                .GetMethod("GetConnectedSsid", BindingFlags.Public | BindingFlags.Instance, null, Type.EmptyTypes, null)
+                ?.Invoke(details, null) as string;
+
+            return string.IsNullOrEmpty(ssid) ? null : ssid;
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Runtime/DiagnosticsPackageService.cs

@@ -45,10 +45,26 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Runtime
         /// </summary>
         public string SasUrlPrefix { get; set; }
 
-        /// <summary>Human-readable error code/message when upload failed. Null on success or skip.</summary>
+        /// <summary>Human-readable error code/message when upload failed or was skipped. Null on success.</summary>
         public string ErrorCode { get; set; }
 
+        /// <summary>
+        /// True when no package was built because a configuration gate said so (mode=Off,
+        /// destination not configured, OnFailure + known success). <see cref="ErrorCode"/>
+        /// then carries the machine-readable gate name so the emitted
+        /// <c>server_action_failed</c> / <c>diagnostics_upload_failed</c> event names the
+        /// actual reason instead of a generic "upload failed".
+        /// </summary>
+        public bool Skipped { get; set; }
+
         public bool Success => BlobName != null;
+
+        public const string SkipModeOff = "diagnostics_skipped_mode_off";
+        public const string SkipNotConfigured = "diagnostics_skipped_not_configured";
+        public const string SkipOnFailureSucceeded = "diagnostics_skipped_onfailure_success";
+
+        public static DiagnosticsUploadResult SkippedBy(string gate) =>
+            new DiagnosticsUploadResult { Skipped = true, ErrorCode = gate };
     }
 
     /// <summary>
@@ -191,7 +207,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Runtime
         /// <summary>
         /// Creates a diagnostics ZIP and uploads it to the configured Blob Storage container.
         /// Returns a DiagnosticsUploadResult with BlobName set on success, or ErrorCode set on failure.
-        /// Returns null if the upload was skipped (mode=Off, not configured, or OnFailure+succeeded).
+        /// A configuration gate (mode=Off, not configured, OnFailure+succeeded) returns a result
+        /// with <see cref="DiagnosticsUploadResult.Skipped"/> and the gate name in ErrorCode.
         /// This method is non-fatal: all exceptions are caught and logged.
         /// </summary>
         /// <param name="enrollmentSucceeded">
@@ -214,14 +231,14 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Runtime
                 var mode = _configuration.DiagnosticsUploadMode ?? "Off";
                 if (string.Equals(mode, "Off", StringComparison.OrdinalIgnoreCase))
                 {
-                    _logger.Debug("Diagnostics upload disabled (mode=Off)");
-                    return null;
+                    _logger.Info("Diagnostics upload skipped: DiagnosticsUploadMode=Off on the running agent.");
+                    return DiagnosticsUploadResult.SkippedBy(DiagnosticsUploadResult.SkipModeOff);
                 }
 
                 if (!_configuration.DiagnosticsUploadEnabled)
                 {
-                    _logger.Debug("Diagnostics upload skipped: not configured for this tenant");
-                    return null;
+                    _logger.Info($"Diagnostics upload skipped: no upload destination configured for this tenant (mode={mode}).");
+                    return DiagnosticsUploadResult.SkippedBy(DiagnosticsUploadResult.SkipNotConfigured);
                 }
 
                 // Null outcome (on-demand mid-session) passes through: the OnFailure gate only
@@ -229,7 +246,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Runtime
                 if (string.Equals(mode, "OnFailure", StringComparison.OrdinalIgnoreCase) && enrollmentSucceeded == true)
                 {
                     _logger.Info("Diagnostics upload skipped: enrollment succeeded and mode=OnFailure");
-                    return null;
+                    return DiagnosticsUploadResult.SkippedBy(DiagnosticsUploadResult.SkipOnFailureSucceeded);
                 }
 
                 _logger.Info($"Creating diagnostics package (mode={mode}, enrollmentSucceeded={(enrollmentSucceeded.HasValue ? enrollmentSucceeded.ToString() : "n/a")}{(fileNameSuffix != null ? $", suffix={fileNameSuffix}" : "")})...");

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/DeviceInfo/DeviceInfoCollector.NetworkAndSecurity.cs

@@ -926,22 +926,23 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.DeviceInfo
             Monitoring.NetworkInterfaceLocator.FindActiveNetworkInterface();
 
         /// <summary>
-        /// Collects WiFi signal info via the native WLAN API (<see cref="WifiInfoReader"/>,
-        /// language-neutral, no process spawn) and emits a separate wifi_signal_info event.
-        /// Designed to run as fire-and-forget via Task.Run — never blocks other collection.
-        /// VMs without WiFi service simply get no event.
+        /// Collects WiFi signal info via <see cref="WifiInfoProvider"/> (native WLAN API → WinRT
+        /// SSID → netsh, all language-neutral bar the last) and emits a separate
+        /// wifi_signal_info event. Designed to run as fire-and-forget via Task.Run — never blocks
+        /// other collection. VMs without WiFi service simply get no event.
         /// </summary>
         private void CollectWiFiSignalInfo(Guid? interfaceGuid)
         {
             try
             {
-                var wifi = WifiInfoReader.TryGetCurrentConnection(interfaceGuid, out var wifiDiag);
+                var wifi = WifiInfoProvider.TryRead(interfaceGuid, out var wifiDiag);
                 if (wifi == null)
                 {
-                    _logger.Debug($"EnrollmentTracker: native WLAN API returned no WiFi info ({wifiDiag ?? "no connected WLAN interface"}) — trying netsh fallback");
-                    wifi = NetshWifiFallback.TryRead();
-                    if (wifi == null)
-                        return;
+                    // Warning, not Debug: the caller only reaches here when the active NIC IS
+                    // WiFi, so a silent miss is a real gap — and Debug is off at the default
+                    // log level, which is what made this invisible in the field.
+                    _logger.Warning($"EnrollmentTracker: no wifi_signal_info — {wifiDiag}");
+                    return;
                 }
 
                 var data = new Dictionary<string, object>();
@@ -953,12 +954,18 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.DeviceInfo
                     data["wifiRadioType"] = wifi.RadioType;
                 if (wifi.Channel.HasValue)
                     data["wifiChannel"] = wifi.Channel.Value;
+                if (wifi.DataLimitedReason != null)
+                    data["wifiDataLimitedReason"] = wifi.DataLimitedReason;
 
                 var message = wifi.Ssid != null ? $"WiFi: {wifi.Ssid}" : "WiFi signal info";
                 if (wifi.SignalPercent.HasValue)
                     message += $", Signal: {wifi.SignalPercent.Value}%";
                 if (wifi.RadioType != null)
                     message += $" ({wifi.RadioType})";
+                // Say it in the timeline too — a missing signal reads like a bug otherwise, and
+                // this is the only place an admin ever learns that a privacy setting caused it.
+                if (wifi.DataLimitedReason == WifiInfoProvider.LocationServicesOff)
+                    message += " — signal unavailable, Location services off";
 
                 EmitDeviceInfoEvent(Constants.EventTypes.WifiSignalInfo, message, data);
             }

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Periodic/NetworkChangeDetector.cs

@@ -390,23 +390,20 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Periodic
         }
 
         /// <summary>
-        /// Collects WiFi SSID, signal, and radio type via the native WLAN API
-        /// (<see cref="WifiInfoReader"/> — language-neutral, no process spawn).
-        /// Synchronous — needed before emitting the event.
+        /// Collects WiFi SSID, signal, and radio type via <see cref="WifiInfoProvider"/>
+        /// (native WLAN API → WinRT SSID → netsh). Synchronous — needed before emitting the event.
         /// </summary>
         private (string ssid, int? signal, string radioType) CollectWiFiInfo(Guid? interfaceGuid)
         {
             try
             {
-                var wifi = WifiInfoReader.TryGetCurrentConnection(interfaceGuid, out var wifiDiag);
-                if (wifi == null)
-                {
-                    _logger.Debug($"NetworkChangeDetector: native WLAN API returned no WiFi info ({wifiDiag ?? "no connected WLAN interface"}) — trying netsh fallback");
-                    wifi = NetshWifiFallback.TryRead();
-                }
-
+                var wifi = WifiInfoProvider.TryRead(interfaceGuid, out var wifiDiag);
                 if (wifi != null)
                     return (wifi.Ssid, wifi.SignalPercent, wifi.RadioType);
+
+                // Warning, not Debug: reached only when the active NIC IS WiFi, and Debug is off
+                // at the default log level — which is what hid this failure in the field.
+                _logger.Warning($"NetworkChangeDetector: no WiFi info for the active WLAN adapter — {wifiDiag}");
             }
             catch (Exception ex)
             {

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Transport/BackendApiClient.cs

@@ -326,10 +326,39 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Transport
                     endpointUnavailable: true);
             }
 
+            // Backend JSON bodies may carry a machine-readable errorCode (Shared
+            // Constants.AgentErrorCodes) that tells the caller how to react — e.g.
+            // session_owner_mismatch → rotate the session id instead of treating this as a
+            // certificate rejection. Absent/unparseable → null, classic auth failure.
+            var errorCode = TryExtractErrorCode(body);
             throw new BackendAuthException(
                 $"Backend returned {statusText}. " +
                 "The device is not authorized. Check client certificate and Autopilot device validation.",
-                (int)response.StatusCode);
+                (int)response.StatusCode,
+                errorCode: errorCode);
+        }
+
+        /// <summary>
+        /// Pulls <c>errorCode</c> out of a backend JSON error body. Tolerant: any parse failure
+        /// or a non-string value yields null, never an exception.
+        /// </summary>
+        internal static string TryExtractErrorCode(string body)
+        {
+            if (string.IsNullOrWhiteSpace(body) || body.TrimStart().Length == 0 || body.TrimStart()[0] != '{')
+                return null;
+            try
+            {
+                var obj = Newtonsoft.Json.Linq.JObject.Parse(body);
+                var token = obj["errorCode"] ?? obj["ErrorCode"];
+                if (token == null || token.Type != Newtonsoft.Json.Linq.JTokenType.String)
+                    return null;
+                var value = (string)token;
+                return string.IsNullOrWhiteSpace(value) ? null : value.Trim();
+            }
+            catch
+            {
+                return null;
+            }
         }
 
         /// <summary>
@@ -429,10 +458,17 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Transport
         /// </summary>
         public bool EndpointUnavailable { get; }
 
-        public BackendAuthException(string message, int statusCode = 0, bool endpointUnavailable = false) : base(message)
+        /// <summary>
+        /// Machine-readable code from the backend's JSON error body (see Shared
+        /// <c>Constants.AgentErrorCodes</c>), or null when the body carried none.
+        /// </summary>
+        public string ErrorCode { get; }
+
+        public BackendAuthException(string message, int statusCode = 0, bool endpointUnavailable = false, string errorCode = null) : base(message)
         {
             StatusCode = statusCode;
             EndpointUnavailable = endpointUnavailable;
+            ErrorCode = errorCode;
         }
     }
 }

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Transport/EmergencyReporter.cs

@@ -28,7 +28,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Transport
         private const int MinIntervalMinutes = 10;
 
         private readonly BackendApiClient _apiClient;
-        private readonly string _sessionId;
+        private volatile string _sessionId;
         private readonly string _tenantId;
         private readonly string _agentVersion;
         private readonly AgentLogger _logger;
@@ -52,6 +52,17 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Transport
             _logger = logger;
         }
 
+        /// <summary>
+        /// SESSION-OWNER-BINDING: the reporter is built before registration and snapshots the
+        /// SessionId; a rotation during registration must be reflected here or later reports
+        /// would name the refused session.
+        /// </summary>
+        public void UpdateSessionId(string sessionId)
+        {
+            if (!string.IsNullOrWhiteSpace(sessionId))
+                _sessionId = sessionId;
+        }
+
         /// <summary>
         /// Attempts to send an emergency report. Returns immediately without awaiting
         /// (intended to be called as fire-and-forget via <c>_ = reporter.TrySendAsync(...)</c>).

src/Agent/AutopilotMonitor.Agent.V2.Core/Orchestration/DecisionStepProcessor.cs

@@ -88,9 +88,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
         private int _passThroughStepsSinceSnapshot; // H1a — pass-through steps skipped since last snapshot
         private bool _parkedTripwireFired; // liveness PR1 — one-shot per agent run, no state-schema touch
 
-        // M1 — parked-tripwire dwell machinery. The timer thread is also what fixes L8: the
+        // M1 — parked-tripwire dwell machinery. The timer thread is also what fixed L8: the
         // tripwire post no longer runs on the ingress worker, so a full channel cannot
-        // self-deadlock on it. Guarded by _parkedLock because the callback races ApplyStep.
+        // self-deadlock on it. (Since 2026-08-29 SignalIngress.Post itself is re-entrancy-safe
+        // — worker-thread posts go to a worker-local queue — so the EffectRunner's
+        // ClassifierVerdictIssued post from inside ApplyStep is covered too.) Guarded by
+        // _parkedLock because the callback races ApplyStep.
         private readonly object _parkedLock = new object();
         private readonly TimeSpan _parkedTripwireDwell;
         private Timer? _parkedDwellTimer;

src/Agent/AutopilotMonitor.Agent.V2.Core/Orchestration/SignalIngress.cs

@@ -27,6 +27,16 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
     /// Die Back-Pressure-Emission läuft NICHT durch den Signal-Channel (würde deadlocken).
     /// </para>
     /// <para>
+    /// <b>Worker re-entrancy</b>: a <see cref="Post"/> issued ON the worker thread itself
+    /// (EffectRunner posting a <c>ClassifierVerdictIssued</c> from inside
+    /// <c>ApplyStep</c>) must never touch the bounded channel — the worker is the channel's
+    /// only consumer, so a full channel would block the consumer as a producer and freeze
+    /// the whole pipeline for the rest of the run. Such posts go to a worker-local
+    /// follow-up queue that the worker drains (ahead of the channel) right after the
+    /// current item finishes. Same processing path, same ordinal/log/reduce semantics —
+    /// just never blocking.
+    /// </para>
+    /// <para>
     /// <b>Shutdown</b>: <see cref="Stop"/> ruft <see cref="BlockingCollection{T}.CompleteAdding"/>,
     /// wartet auf das Drain-Ende via <c>Thread.Join</c>. Nach <c>Stop</c> wirft jeder
     /// weitere <see cref="Post"/> <see cref="InvalidOperationException"/>.
@@ -79,6 +89,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
         private readonly object _backPressureLock = new object();
 
         private Thread? _worker;
+        // Worker-thread-only: signals posted re-entrantly from ApplyStep (EffectRunner
+        // classifier verdicts). Drained by WorkerLoop after every channel item, before the
+        // next channel item is taken. Only the worker enqueues and dequeues — no lock.
+        private readonly Queue<IngressItem> _workerLocalQueue = new Queue<IngressItem>();
+        private long _reentrantPostCount;
         private long _nextSignalOrdinal;     // worker-thread-only after Start; seeded from SignalLog
         private int _started;                 // 0 = not started, 1 = running
         private int _stopRequested;           // 0 = live, 1 = Stop called
@@ -135,6 +150,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
         /// </summary>
         public long PendingSignalCount => Interlocked.Read(ref _unprocessedCount);
 
+        /// <summary>
+        /// Signals that were posted from the worker thread itself and routed through the
+        /// worker-local follow-up queue instead of the bounded channel. Observability/tests.
+        /// </summary>
+        public long ReentrantPostCount => Interlocked.Read(ref _reentrantPostCount);
+
         /// <summary>
         /// Fires synchronously from <see cref="Post"/> after a signal has been accepted into
         /// the channel (for both the fast-path <see cref="BlockingCollection{T}.TryAdd"/> and
@@ -218,6 +239,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
         /// Reicht ein Raw-/Derived-/Synthetic-Signal in den Ingress ein. Thread-safe; darf von
         /// beliebig vielen Collector-Threads (und vom <see cref="EffectRunner"/>) parallel
         /// gerufen werden. Blockiert, wenn der Channel voll ist — Plan §2.1a Back-Pressure.
+        /// Ausnahme: Aufrufe vom Worker-Thread selbst blockieren nie (worker-local queue).
         /// </summary>
         public void Post(
             DecisionSignalKind kind,
@@ -228,10 +250,6 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             int kindSchemaVersion = 1,
             object? typedPayload = null)
         {
-            if (Volatile.Read(ref _stopRequested) == 1 || _channel.IsAddingCompleted)
-            {
-                throw new InvalidOperationException("SignalIngress has been stopped.");
-            }
             if (evidence == null)
             {
                 throw new ArgumentNullException(nameof(evidence));
@@ -243,6 +261,30 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
 
             var item = new IngressItem(kind, kindSchemaVersion, occurredAtUtc, sourceOrigin, evidence, payload, typedPayload);
 
+            // Worker re-entrancy (see class doc): a post from the worker thread itself goes to
+            // the worker-local follow-up queue, never into the bounded channel. Checked before
+            // the stop gate on purpose — while Stop() drains the channel the worker may still
+            // produce verdicts for the items it is finishing, and those must not be lost.
+            if (ReferenceEquals(Thread.CurrentThread, _worker))
+            {
+                Interlocked.Increment(ref _unprocessedCount);
+                _workerLocalQueue.Enqueue(item);
+                Interlocked.Increment(ref _reentrantPostCount);
+                if (_workerLocalQueue.Count > 1)
+                {
+                    // One follow-up per step is the expected shape (one RunClassifier effect).
+                    // More means effects are chaining on the worker — worth seeing in the log.
+                    _logger?.Debug($"SignalIngress: worker-local follow-up queue depth={_workerLocalQueue.Count} kind={kind} origin={sourceOrigin}");
+                }
+                RaiseSignalPosted(kind, payload);
+                return;
+            }
+
+            if (Volatile.Read(ref _stopRequested) == 1 || _channel.IsAddingCompleted)
+            {
+                throw new InvalidOperationException("SignalIngress has been stopped.");
+            }
+
             // Codex Finding 2 (2026-04-30): bump the pending-counter BEFORE handing the item
             // to the channel. Decrement in three places: (a) when TryAdd throws because
             // CompleteAdding raced between the post-stop check and the enqueue, (b) when
@@ -353,6 +395,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
                 foreach (var item in _channel.GetConsumingEnumerable())
                 {
                     ProcessItem(item);
+                    DrainWorkerLocalQueue();
                 }
             }
             catch (Exception ex)
@@ -366,6 +409,19 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             }
         }
 
+        /// <summary>
+        /// Processes signals the worker posted to itself during the previous item (see class
+        /// doc, worker re-entrancy). Iterative, not recursive: a follow-up that produces
+        /// another follow-up is simply appended and handled in the same loop.
+        /// </summary>
+        private void DrainWorkerLocalQueue()
+        {
+            while (_workerLocalQueue.Count > 0)
+            {
+                ProcessItem(_workerLocalQueue.Dequeue());
+            }
+        }
+
         private void ProcessItem(IngressItem item)
         {
             // Codex Finding 2 (2026-04-30): match the Interlocked.Increment that Post()

src/Agent/AutopilotMonitor.Agent.V2.Core/Security/SessionIdPersistence.cs

@@ -175,6 +175,27 @@ namespace AutopilotMonitor.Agent.V2.Core.Security
             }
         }
 
+        /// <summary>
+        /// Replaces the persisted SessionId with a fresh GUID and restarts the session-age clock.
+        /// Used when the backend answers register-session with <c>session_owner_mismatch</c>
+        /// (SESSION-OWNER-BINDING): the id on disk belongs to a session bound to a different device
+        /// identity — the re-enroll-without-wipe shape — so this run must become a new session.
+        /// Unlike <see cref="Delete"/> this leaves <c>whiteglove.complete</c> untouched: a Part-2
+        /// resume that has to rotate is still a Part-2 resume.
+        /// </summary>
+        /// <returns>The new SessionId.</returns>
+        public string Rotate(AgentLogger logger = null)
+        {
+            lock (_lockObject)
+            {
+                var fresh = Guid.NewGuid().ToString();
+                WriteAtomic(fresh, logger);
+                SaveSessionCreatedAtInternal(DateTime.UtcNow);
+                logger?.Info($"SessionIdPersistence: rotated SessionId to {fresh}.");
+                return fresh;
+            }
+        }
+
         private static void TryDelete(string path, AgentLogger logger)
         {
             try { if (File.Exists(path)) File.Delete(path); }

src/Agent/AutopilotMonitor.Agent.V2.Core/Security/SessionRegistrationHelper.cs

@@ -4,6 +4,7 @@ using AutopilotMonitor.Agent.V2.Core.Configuration;
 using AutopilotMonitor.Agent.V2.Core.Logging;
 using AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.DeviceInfo;
 using AutopilotMonitor.Agent.V2.Core.Monitoring.Transport;
+using AutopilotMonitor.Shared;
 using AutopilotMonitor.Shared.Models;
 
 namespace AutopilotMonitor.Agent.V2.Core.Security
@@ -33,6 +34,13 @@ namespace AutopilotMonitor.Agent.V2.Core.Security
     ///     <see cref="AuthFailureTracker"/> (which fires the first-failure distress + may trip
     ///     the shutdown threshold) and return <see cref="SessionRegistrationOutcome.AuthFailed"/>
     ///     without retrying — the backend has definitively rejected the device cert.</item>
+    ///   <item>Exception to the above — a 403 carrying error code
+    ///     <c>session_owner_mismatch</c> (SESSION-OWNER-BINDING): the persisted SessionId names a
+    ///     session bound to another device identity (typically an Intune re-enrollment without a
+    ///     wipe, where <c>session.id</c> survived but the certificate identity changed). That is
+    ///     not an auth failure: the session is rotated through <c>rotateSession</c> and
+    ///     registration retried exactly once. The tracker is NOT fed — five of these would
+    ///     otherwise soft-shutdown a perfectly authorized agent.</item>
     ///   <item>Any other exception on the last attempt → <see cref="EmergencyReporter.TrySendAsync"/>
     ///     with <c>AgentErrorType.RegisterSessionFailed</c> so operators see the final cause.</item>
     /// </list>
@@ -72,7 +80,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Security
             Func<int, Task> backoffDelay = null,
             Func<Exception, Task> onTerminalTransportFailure = null,
             (string Manufacturer, string Model, string SerialNumber)? deviceHardware = null,
-            Func<AgentLogger, Task> networkLinkWait = null)
+            Func<AgentLogger, Task> networkLinkWait = null,
+            Func<string> rotateSession = null)
         {
             if (apiClient == null) throw new ArgumentNullException(nameof(apiClient));
             if (agentConfig == null) throw new ArgumentNullException(nameof(agentConfig));
@@ -86,6 +95,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Security
             catch (Exception ex) { logger.Debug($"Pre-registration network wait failed ({ex.Message}) — registering anyway."); }
             string lastError = null;
             Exception lastException = null;
+            string rotatedFromSessionId = null;
 
             for (int attempt = 1; attempt <= MaxAttempts; attempt++)
             {
@@ -97,12 +107,38 @@ namespace AutopilotMonitor.Agent.V2.Core.Security
                     if (response != null && response.Success)
                     {
                         logger.Info($"Session registered successfully: {response.SessionId} (validatedBy={response.ValidatedBy}, adminAction={response.AdminAction ?? "(none)"})");
-                        return SessionRegistrationResult.Succeeded(response);
+                        return SessionRegistrationResult.Succeeded(response, rotatedFromSessionId);
                     }
 
                     lastError = response?.Message ?? "(null response)";
                     logger.Warning($"Session registration failed: {lastError}");
                 }
+                catch (BackendAuthException ex) when (
+                    ex.ErrorCode == Constants.AgentErrorCodes.SessionOwnerMismatch
+                    && rotateSession != null
+                    && rotatedFromSessionId == null)
+                {
+                    // SESSION-OWNER-BINDING: the id on disk belongs to a session this device
+                    // identity does not own. Become a new session and register once more —
+                    // immediately, no backoff, no auth-failure bookkeeping.
+                    rotatedFromSessionId = registration.SessionId;
+                    string newSessionId;
+                    try
+                    {
+                        newSessionId = rotateSession();
+                    }
+                    catch (Exception rotateEx)
+                    {
+                        logger.Error($"Session owner mismatch reported by backend but session rotation failed: {rotateEx.Message}", rotateEx);
+                        authFailureTracker?.RecordFailure(ex.StatusCode, "agent/register-session", ex.EndpointUnavailable);
+                        return SessionRegistrationResult.AuthFailed(ex.StatusCode, ex.Message);
+                    }
+                    logger.Warning(
+                        $"Backend refused registration with {Constants.AgentErrorCodes.SessionOwnerMismatch}: session {rotatedFromSessionId} " +
+                        $"is bound to another device identity (re-enrollment without wipe?). Rotated to {newSessionId}; re-registering.");
+                    registration = BuildRegistration(agentConfig, agentVersion, deviceHardware);
+                    continue;
+                }
                 catch (BackendAuthException ex)
                 {
                     logger.Error($"Session registration authentication failed ({ex.StatusCode}): {ex.Message}");
@@ -237,20 +273,29 @@ namespace AutopilotMonitor.Agent.V2.Core.Security
         public string AdminAction => Response?.AdminAction;
         public ValidatorType ValidatedBy => Response?.ValidatedBy ?? ValidatorType.Unknown;
 
+        /// <summary>
+        /// SESSION-OWNER-BINDING: the SessionId this run started with when the backend refused it
+        /// with <c>session_owner_mismatch</c> and the session was rotated before the successful
+        /// registration. Null on the normal path.
+        /// </summary>
+        public string RotatedFromSessionId { get; }
+
         private SessionRegistrationResult(
             SessionRegistrationOutcome outcome,
             RegisterSessionResponse response,
             int httpStatusCode,
-            string errorMessage)
+            string errorMessage,
+            string rotatedFromSessionId = null)
         {
             Outcome = outcome;
             Response = response;
             HttpStatusCode = httpStatusCode;
             ErrorMessage = errorMessage;
+            RotatedFromSessionId = rotatedFromSessionId;
         }
 
-        public static SessionRegistrationResult Succeeded(RegisterSessionResponse response)
-            => new SessionRegistrationResult(SessionRegistrationOutcome.Succeeded, response, 200, null);
+        public static SessionRegistrationResult Succeeded(RegisterSessionResponse response, string rotatedFromSessionId = null)
+            => new SessionRegistrationResult(SessionRegistrationOutcome.Succeeded, response, 200, null, rotatedFromSessionId);
 
         public static SessionRegistrationResult AuthFailed(int statusCode, string message)
             => new SessionRegistrationResult(SessionRegistrationOutcome.AuthFailed, null, statusCode, message);

src/Agent/AutopilotMonitor.Agent.V2/Program.cs

@@ -269,7 +269,9 @@ namespace AutopilotMonitor.Agent.V2
             // mapping + on-failure client disposal) is encapsulated in BackendSessionRegistration.
             // Exit codes: 6 = AuthFailed, 7 = anything else. See Runtime/BackendSessionRegistration.cs.
             var registration = Runtime.BackendSessionRegistration.Register(
-                bootstrap.AgentConfig, auth, telemetry.MtlsHttpClient, GetAgentVersion(), consoleMode, logger);
+                bootstrap.AgentConfig, auth, telemetry.MtlsHttpClient, GetAgentVersion(), consoleMode, logger,
+                rotateSession: () => Runtime.BackendSessionRegistration.RotateSession(
+                    bootstrap.AgentConfig, bootstrap.SessionPersistence, auth, transportDir, logger));
             if (registration.ShouldExit)
             {
                 return registration.ExitCode;

src/Agent/AutopilotMonitor.Agent.V2/Runtime/AgentRuntimeConfig.cs

@@ -115,10 +115,11 @@ namespace AutopilotMonitor.Agent.V2.Runtime
 
         /// <summary>
         /// Applies a live-fetched config to the runtime: merge, tracker ceilings, log level,
-        /// integrity SHA + check, bootstrap-config cleanup. Shared by the Phase 4 startup path
-        /// and the post-registration recovery path so both apply identical semantics.
+        /// integrity SHA + check, bootstrap-config cleanup. Shared by the Phase 4 startup path,
+        /// the post-registration recovery path and the live <c>rotate_config</c> ServerAction
+        /// (<see cref="ServerControlPlane.BuildDispatcher"/>) so all three apply identical semantics.
         /// </summary>
-        private static RemoteConfigMergeResult ApplyFetchedConfig(
+        internal static RemoteConfigMergeResult ApplyFetchedConfig(
             AgentConfiguration agentConfig,
             AgentConfigResponse remoteConfig,
             BackendAuthBundle auth,

src/Agent/AutopilotMonitor.Agent.V2/Runtime/AgentRuntimeHost.cs

@@ -344,7 +344,8 @@ namespace AutopilotMonitor.Agent.V2.Runtime
                         orchestrator.Start(ingress =>
                         {
                             lifecyclePost = new InformationalEventPost(ingress, SystemClock.Instance, logger);
-                            LifecycleEmitters.EmitAgentStarted(lifecyclePost, agentConfig, previousExit, agentVersion, remoteConfigService, logger);
+                            LifecycleEmitters.EmitAgentStarted(lifecyclePost, agentConfig, previousExit, agentVersion, remoteConfigService, logger,
+                                rotatedFromSessionId: registrationResult?.RotatedFromSessionId);
                             // Wire-visible signal that the agent is running on defaults/cache
                             // rather than the live tenant config — closes the cold-start
                             // blind spot observed in session 8f2bef72 (2026-05-19).
@@ -420,6 +421,9 @@ namespace AutopilotMonitor.Agent.V2.Runtime
                                 terminationHandler: terminationHandler,
                                 remoteConfigService: remoteConfigService,
                                 diagnosticsService: diagnosticsService,
+                                auth: auth,
+                                agentVersion: agentVersion,
+                                consoleMode: consoleMode,
                                 shutdown: shutdown,
                                 shutdownComplete: shutdownComplete,
                                 post: lifecyclePost,

src/Agent/AutopilotMonitor.Agent.V2/Runtime/BackendSessionRegistration.cs

@@ -27,7 +27,8 @@ namespace AutopilotMonitor.Agent.V2.Runtime
             HttpClient mtlsHttpClient,
             string agentVersion,
             bool consoleMode,
-            AgentLogger logger)
+            AgentLogger logger,
+            Func<string> rotateSession = null)
         {
             if (agentConfig == null) throw new ArgumentNullException(nameof(agentConfig));
             if (auth == null) throw new ArgumentNullException(nameof(auth));
@@ -43,7 +44,8 @@ namespace AutopilotMonitor.Agent.V2.Runtime
                 onTerminalTransportFailure: ex => DiagnoseTerminalTransportFailure(ex, auth, logger),
                 // Reuse the single hardened hardware read from the auth bundle so the session row
                 // matches the security headers the backend validated against (no second WMI query).
-                deviceHardware: (auth.Manufacturer, auth.Model, auth.SerialNumber))
+                deviceHardware: (auth.Manufacturer, auth.Model, auth.SerialNumber),
+                rotateSession: rotateSession)
                 .GetAwaiter().GetResult();
 
             if (registrationResult.Outcome != SessionRegistrationOutcome.Succeeded)
@@ -63,6 +65,48 @@ namespace AutopilotMonitor.Agent.V2.Runtime
             return SessionRegistrationOutcomeResult.Continue(registrationResult);
         }
 
+        /// <summary>
+        /// SESSION-OWNER-BINDING: the one place that turns "backend says this session id is not
+        /// ours" into a new session. Rotates the persisted id, points the runtime config at it,
+        /// drops the transport spool (its lines carry the refused session's partition key and
+        /// would otherwise be uploaded against it after the rotation) and re-targets the
+        /// emergency reporter, which snapshotted the id before registration. Everything else
+        /// reads <c>agentConfig.SessionId</c> live after Phase 6.
+        /// </summary>
+        internal static string RotateSession(
+            AgentConfiguration agentConfig,
+            SessionIdPersistence sessionPersistence,
+            BackendAuthBundle auth,
+            string transportDir,
+            AgentLogger logger)
+        {
+            var newSessionId = sessionPersistence.Rotate(logger);
+            agentConfig.SessionId = newSessionId;
+            auth?.EmergencyReporter?.UpdateSessionId(newSessionId);
+            DropTransportSpool(transportDir, logger);
+            return newSessionId;
+        }
+
+        private static void DropTransportSpool(string transportDir, AgentLogger logger)
+        {
+            if (string.IsNullOrWhiteSpace(transportDir)) return;
+            foreach (var name in new[] { "spool.jsonl", "upload-cursor.json" })
+            {
+                var path = System.IO.Path.Combine(transportDir, name);
+                try
+                {
+                    if (!System.IO.File.Exists(path)) continue;
+                    var size = new System.IO.FileInfo(path).Length;
+                    System.IO.File.Delete(path);
+                    logger.Info($"Session rotation: dropped {name} ({size} bytes) — its items belonged to the refused session.");
+                }
+                catch (Exception ex)
+                {
+                    logger.Warning($"Session rotation: could not drop {name}: {ex.Message}");
+                }
+            }
+        }
+
         /// <summary>
         /// Off-hot-path diagnostic invoked once after all session-registration retries fail.
         /// Detects whether the terminal exception was a TLS-layer <c>SecureChannelFailure</c>

src/Agent/AutopilotMonitor.Agent.V2/Runtime/LifecycleEmitters.cs

@@ -42,7 +42,8 @@ namespace AutopilotMonitor.Agent.V2.Runtime
             Program.PreviousExitSummary previousExit,
             string agentVersion,
             RemoteConfigService remoteConfigService,
-            AgentLogger logger)
+            AgentLogger logger,
+            string rotatedFromSessionId = null)
         {
             try
             {
@@ -67,6 +68,11 @@ namespace AutopilotMonitor.Agent.V2.Runtime
                     { "diagnosticsUploadMode", agentConfig.DiagnosticsUploadMode ?? "Off" },
                     { "previousExitType", previousExit?.ExitType ?? "unknown" },
                     { "unrestrictedMode", agentConfig.UnrestrictedMode },
+                    // SESSION-OWNER-BINDING: true when the backend refused the persisted session
+                    // id (session_owner_mismatch) and this run rotated to a new session before
+                    // registering — the re-enroll-without-wipe shape, made visible on the timeline.
+                    { "sessionRotated", rotatedFromSessionId != null },
+                    { "previousSessionId", rotatedFromSessionId ?? string.Empty },
                     // remoteConfigFetched answers "is the agent running on a live-fetched
                     // config" — true also when the post-registration recovery replaced a
                     // failed startup fetch (remoteConfigOutcome then still names the startup

src/Agent/AutopilotMonitor.Agent.V2/Runtime/ServerControlPlane.cs

@@ -33,6 +33,9 @@ namespace AutopilotMonitor.Agent.V2.Runtime
             EnrollmentTerminationHandler terminationHandler,
             RemoteConfigService remoteConfigService,
             DiagnosticsPackageService diagnosticsService,
+            BackendAuthBundle auth,
+            string agentVersion,
+            bool consoleMode,
             ManualResetEventSlim shutdown,
             ManualResetEventSlim shutdownComplete,
             InformationalEventPost post,
@@ -41,9 +44,31 @@ namespace AutopilotMonitor.Agent.V2.Runtime
             return new ServerActionDispatcher(
                 configuration: agentConfig,
                 logger: logger,
+                // rotate_config = fetch AND apply. FetchConfigAsync only stores the response
+                // in RemoteConfigService.CurrentConfig; the projection onto the live
+                // AgentConfiguration (DiagnosticsUploadMode, LogLevel, SelfDestruct, ...)
+                // is ApplyFetchedConfig — the same path the startup fetch uses. Without it
+                // the portal's "enable diagnostics, then collect" flow fetched the new
+                // config and still ran the diagnostics gate against the stale mode.
+                // FetchConfigAsync never throws: a failed fetch falls back to cache/defaults
+                // and reports it via LastFetchOutcome — that is NOT an executed rotation.
                 rotateConfigAsync: async () =>
                 {
-                    try { var _ = await remoteConfigService.FetchConfigAsync(); return true; }
+                    try
+                    {
+                        var fetched = await remoteConfigService.FetchConfigAsync();
+                        if (remoteConfigService.LastFetchOutcome != RemoteConfigFetchOutcome.Succeeded)
+                        {
+                            logger.Warning($"ServerAction rotate_config: live fetch failed (outcome={remoteConfigService.LastFetchOutcome}, {remoteConfigService.LastFetchFailureMessage}) — runtime config unchanged.");
+                            return false;
+                        }
+
+                        var mergeResult = AgentRuntimeConfig.ApplyFetchedConfig(
+                            agentConfig, fetched, auth, agentVersion, consoleMode, logger);
+                        LifecycleEmitters.EmitUnrestrictedModeAuditIfChanged(post, agentConfig, mergeResult, logger);
+                        logger.Info($"ServerAction rotate_config: applied ConfigVersion={fetched.ConfigVersion} to the running agent.");
+                        return true;
+                    }
                     catch (Exception ex) { logger.Warning($"ServerAction rotate_config failed: {ex.Message}"); return false; }
                 },
                 // On-demand request mid-enrollment — the session has no outcome yet. Null keeps

src/Backend/AutopilotMonitor.Functions.Tests/AdminIdentityBindingAuthorizationTests.cs

@@ -0,0 +1,231 @@
+using System.Security.Claims;
+using AutopilotMonitor.Functions.Middleware;
+using AutopilotMonitor.Functions.Security;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared;
+using AutopilotMonitor.Shared.DataAccess;
+using AutopilotMonitor.Shared.Models;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// End-to-end authorization effect of identity binding through <see cref="PolicyEnforcementMiddleware"/>:
+/// a validly-signed token from a FOREIGN Entra tenant (the API accepts every tenant) whose upn matches a
+/// GlobalAdmins / DelegatedAdmins row must resolve NO platform or delegated role — and likewise a token
+/// from the home tenant under a different object id, a token without an oid, and any UPN whose role row
+/// has no binding at all. Also pins the ordering inside <see cref="DelegatedAdminService"/>: binding is
+/// checked before the Pro entitlement gate, and an unbound caller never triggers the edition lookup.
+/// </summary>
+public class AdminIdentityBindingAuthorizationTests
+{
+    private const string HomeTenant = "11111111-1111-1111-1111-111111111111";
+    private const string AttackerTenant = "22222222-2222-2222-2222-222222222222";
+    private const string ManagedTenant = "33333333-3333-3333-3333-333333333333";
+    private const string GaUpn = "cloudadmin@vendor.example";
+    private const string MspUpn = "msp@partner.example";
+    private const string Oid = "aaaaaaaa-1111-1111-1111-aaaaaaaaaaaa";
+    private const string OtherOid = "bbbbbbbb-2222-2222-2222-bbbbbbbbbbbb";
+
+    private sealed class Harness
+    {
+        public required PolicyEnforcementMiddleware Middleware { get; init; }
+        public required Mock<IAdminRepository> Repo { get; init; }
+    }
+
+    private static Harness Build(AdminIdentityBinding? binding, string? globalRole = null, string? delegatedTenant = null)
+    {
+        var repo = new Mock<IAdminRepository>();
+        repo.Setup(r => r.GetGlobalRoleAsync(It.IsAny<string>())).ReturnsAsync(globalRole);
+        repo.Setup(r => r.GetTenantMemberAsync(It.IsAny<string>(), It.IsAny<string>())).ReturnsAsync((TenantMember?)null);
+        repo.Setup(r => r.GetDelegatedTenantsAsync(It.IsAny<string>())).ReturnsAsync(
+            delegatedTenant == null
+                ? new List<DelegatedAdminEntry>()
+                : new List<DelegatedAdminEntry>
+                {
+                    new()
+                    {
+                        Upn = MspUpn, TenantId = delegatedTenant.ToLowerInvariant(),
+                        Role = Constants.DelegatedRoles.DelegatedReader, IsEnabled = true,
+                        Status = Constants.DelegatedStatus.Active, Source = Constants.DelegatedSource.OperatorGranted,
+                    },
+                });
+        repo.Setup(r => r.GetGroupAssignmentsForUpnAsync(It.IsAny<string>())).ReturnsAsync(new List<TenantGroupAssignment>());
+        repo.Setup(r => r.GetIdentityBindingAsync(It.IsAny<string>())).ReturnsAsync(() => binding);
+        repo.Setup(r => r.TryPinIdentityObjectIdAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .ReturnsAsync((string _, string tid, string oid) =>
+            {
+                if (binding != null && !binding.IsObjectIdPinned && binding.TenantId == tid)
+                    binding.ObjectId = oid;
+                return binding;
+            });
+
+        var configRepo = new Mock<IConfigRepository>();
+        configRepo.Setup(r => r.GetTenantConfigurationAsync(It.IsAny<string>())).ReturnsAsync((TenantConfiguration?)null);
+
+        var cache = new MemoryCache(new MemoryCacheOptions());
+        var bindings = new AdminIdentityBindingService(repo.Object, cache, NullLogger<AdminIdentityBindingService>.Instance);
+        var globalAdmin = new GlobalAdminService(repo.Object, bindings, cache, NullLogger<GlobalAdminService>.Instance);
+        var delegatedAdmin = new DelegatedAdminService(
+            repo.Object, bindings,
+            new StubTenantEntitlementService(TenantEdition.Pro),
+            cache, NullLogger<DelegatedAdminService>.Instance);
+        var tenantAdmins = new TenantAdminsService(repo.Object, cache, NullLogger<TenantAdminsService>.Instance);
+        var tenantConfig = new TenantConfigurationService(configRepo.Object, NullLogger<TenantConfigurationService>.Instance, cache);
+
+        return new Harness
+        {
+            Middleware = new PolicyEnforcementMiddleware(
+                NullLogger<PolicyEnforcementMiddleware>.Instance, globalAdmin, delegatedAdmin, tenantAdmins, tenantConfig),
+            Repo = repo,
+        };
+    }
+
+    private static ClaimsPrincipal Token(string tenantId, string upn, string? oid = Oid)
+    {
+        var claims = new List<Claim> { new("tid", tenantId), new("upn", upn) };
+        if (oid != null) claims.Add(new Claim("oid", oid));
+        return new ClaimsPrincipal(new ClaimsIdentity(claims, "TestAuth"));
+    }
+
+    private static AdminIdentityBinding Bound(string upn, string tenantId, string objectId = Oid)
+        => new() { Upn = upn, TenantId = tenantId, ObjectId = objectId };
+
+    // ── Global Admin tier ─────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task BoundGlobalAdmin_FromHomeTenant_IsAdmitted()
+    {
+        var h = Build(Bound(GaUpn, HomeTenant), globalRole: Constants.GlobalRoles.GlobalAdmin);
+        var r = await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(HomeTenant, GaUpn));
+        Assert.True(r.Allowed);
+        Assert.True(r.Context!.IsGlobalAdmin);
+    }
+
+    [Theory]
+    [InlineData("GET", "/api/global/raw/tables")]       // GlobalAdminOnly — raw table dump incl. tenant secrets
+    [InlineData("POST", "/api/auth/global-admins")]     // GlobalAdminOnly — persist access
+    [InlineData("GET", "/api/config/all")]              // GlobalReadOrDelegatedSubset
+    [InlineData("GET", "/api/auth/global-admins")]      // GlobalReadOrAdmin
+    public async Task ForeignTenantToken_WithGlobalAdminUpn_IsDenied(string method, string path)
+    {
+        // The finding: attacker registers the lapsed GA domain in their own tenant, creates the same UPN,
+        // signs in (any tenant is accepted) — the token is genuine, only the tid differs.
+        var h = Build(Bound(GaUpn, HomeTenant), globalRole: Constants.GlobalRoles.GlobalAdmin);
+        var r = await h.Middleware.DecideAsync(method, path, null, Token(AttackerTenant, GaUpn));
+        Assert.False(r.Allowed, $"{method} {path} must deny a foreign-tenant token even with a matching GA UPN");
+    }
+
+    [Fact]
+    public async Task ForeignTenantToken_WithGlobalAdminUpn_CannotReachAnotherTenant()
+    {
+        // Cross-tenant read on a tenant-scoped route: no GlobalScope ⇒ the cross-tenant guard blocks.
+        var h = Build(Bound(GaUpn, HomeTenant), globalRole: Constants.GlobalRoles.GlobalAdmin);
+        var r = await h.Middleware.DecideAsync("GET", $"/api/config/{ManagedTenant}", null, Token(AttackerTenant, GaUpn));
+        Assert.False(r.Allowed);
+    }
+
+    [Fact]
+    public async Task HomeTenantToken_DifferentObjectId_IsDenied()
+    {
+        // UPN recycled inside the home tenant (User Administrator re-assigns it to another account).
+        var h = Build(Bound(GaUpn, HomeTenant, Oid), globalRole: Constants.GlobalRoles.GlobalAdmin);
+        var r = await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(HomeTenant, GaUpn, OtherOid));
+        Assert.False(r.Allowed);
+    }
+
+    [Fact]
+    public async Task TokenWithoutObjectId_ResolvesNoPlatformRole()
+    {
+        var h = Build(Bound(GaUpn, HomeTenant), globalRole: Constants.GlobalRoles.GlobalAdmin);
+        var r = await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(HomeTenant, GaUpn, oid: null));
+        Assert.False(r.Allowed);
+    }
+
+    [Fact]
+    public async Task UnboundGlobalAdminRow_IsInert()
+    {
+        // Legacy row, no binding yet: fail-closed until the operator seeds the binding — never "first come".
+        var h = Build(binding: null, globalRole: Constants.GlobalRoles.GlobalAdmin);
+        Assert.False((await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(HomeTenant, GaUpn))).Allowed);
+        Assert.False((await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(AttackerTenant, GaUpn))).Allowed);
+    }
+
+    [Fact]
+    public async Task UnpinnedBinding_HomeTenantFirstSignIn_Pins_ThenForeignAndRecycledAreDenied()
+    {
+        var h = Build(Bound(GaUpn, HomeTenant, objectId: ""), globalRole: Constants.GlobalRoles.GlobalAdmin);
+
+        // First sign-in from the bound tenant pins the oid and is admitted.
+        Assert.True((await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(HomeTenant, GaUpn, Oid))).Allowed);
+        h.Repo.Verify(r => r.TryPinIdentityObjectIdAsync(GaUpn, HomeTenant, Oid), Times.Once);
+
+        // From then on: same account ok, another account in the home tenant denied, foreign tenant denied.
+        Assert.True((await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(HomeTenant, GaUpn, Oid))).Allowed);
+        Assert.False((await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(HomeTenant, GaUpn, OtherOid))).Allowed);
+        Assert.False((await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(AttackerTenant, GaUpn, Oid))).Allowed);
+    }
+
+    [Fact]
+    public async Task UnpinnedBinding_ForeignTenantCannotClaimThePin()
+    {
+        var h = Build(Bound(GaUpn, HomeTenant, objectId: ""), globalRole: Constants.GlobalRoles.GlobalAdmin);
+
+        Assert.False((await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(AttackerTenant, GaUpn, OtherOid))).Allowed);
+        h.Repo.Verify(r => r.TryPinIdentityObjectIdAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+
+        // The real admin still gets the pin afterwards.
+        Assert.True((await h.Middleware.DecideAsync("GET", "/api/global/raw/tables", null, Token(HomeTenant, GaUpn, Oid))).Allowed);
+    }
+
+    // ── Delegated (MSP) tier ──────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task BoundDelegatedAdmin_FromHomeTenant_IsRescuedOnManagedTenantRead()
+    {
+        var h = Build(Bound(MspUpn, HomeTenant), delegatedTenant: ManagedTenant);
+        var r = await h.Middleware.DecideAsync("GET", $"/api/config/{ManagedTenant}", null, Token(HomeTenant, MspUpn));
+        Assert.True(r.Allowed);
+        Assert.True(r.Context!.IsDelegatedReader);
+    }
+
+    [Fact]
+    public async Task ForeignTenantToken_WithDelegatedUpn_ResolvesEmptyScope()
+    {
+        // The finding's MSP variant: an attacker tenant (Pro via self-service trial) mints the delegated UPN.
+        var h = Build(Bound(MspUpn, HomeTenant), delegatedTenant: ManagedTenant);
+        var r = await h.Middleware.DecideAsync("GET", $"/api/config/{ManagedTenant}", null, Token(AttackerTenant, MspUpn));
+        Assert.False(r.Allowed);
+        Assert.False((await h.Middleware.DecideAsync("GET", "/api/config/all", null, Token(AttackerTenant, MspUpn))).Allowed);
+    }
+
+    [Fact]
+    public async Task DelegatedService_ChecksBindingBeforeEntitlementGate()
+    {
+        var repo = new Mock<IAdminRepository>();
+        repo.Setup(r => r.GetDelegatedTenantsAsync(It.IsAny<string>())).ReturnsAsync(new List<DelegatedAdminEntry>
+        {
+            new()
+            {
+                Upn = MspUpn, TenantId = ManagedTenant, Role = Constants.DelegatedRoles.DelegatedReader,
+                IsEnabled = true, Status = Constants.DelegatedStatus.Active, Source = Constants.DelegatedSource.OperatorGranted,
+            },
+        });
+        repo.Setup(r => r.GetGroupAssignmentsForUpnAsync(It.IsAny<string>())).ReturnsAsync(new List<TenantGroupAssignment>());
+        var editionLookups = 0;
+        var svc = new DelegatedAdminService(
+            repo.Object,
+            new StubAdminIdentityBindingService(bound: false),
+            new StubTenantEntitlementService(_ => { editionLookups++; return TenantEdition.Pro; }),
+            new MemoryCache(new MemoryCacheOptions()),
+            NullLogger<DelegatedAdminService>.Instance);
+
+        var scope = await svc.GetScopeAsync(new AdminIdentity(MspUpn, AttackerTenant, Oid));
+
+        Assert.True(scope.IsEmpty);
+        Assert.Equal(0, editionLookups);
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/AdminIdentityBindingServiceTests.cs

@@ -0,0 +1,242 @@
+using AutopilotMonitor.Functions.Security;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.DataAccess;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Pins <see cref="AdminIdentityBindingService"/> — the one place that decides whether a caller IS the
+/// identity a cross-tenant-role UPN was granted for. The API accepts tokens from any Entra tenant and
+/// upn/preferred_username are mutable, so a UPN string alone must never resolve a platform or delegated
+/// role: only the (upn, tid, oid) triple matching the stored binding does. Covers the verdict matrix
+/// (no binding / tenant mismatch / first-sign-in pin / pinned mismatch / concurrent-pin loss), the cache
+/// invalidation after a pin, and the grant-time conflict rules (a grant never silently re-homes a UPN).
+/// </summary>
+public class AdminIdentityBindingServiceTests
+{
+    private const string Upn = "admin@vendor.example";
+    private const string HomeTenant = "11111111-1111-1111-1111-111111111111";
+    private const string ForeignTenant = "22222222-2222-2222-2222-222222222222";
+    private const string Oid = "aaaaaaaa-1111-1111-1111-aaaaaaaaaaaa";
+    private const string OtherOid = "bbbbbbbb-2222-2222-2222-bbbbbbbbbbbb";
+
+    private static (AdminIdentityBindingService Svc, Mock<IAdminRepository> Repo) Build(AdminIdentityBinding? stored)
+    {
+        var repo = new Mock<IAdminRepository>();
+        // Stateful stand-in for the row: reads return `stored`, a pin mutates it under the repo's contract
+        // (only onto an unpinned row homed in the caller's tenant), upserts replace it.
+        repo.Setup(r => r.GetIdentityBindingAsync(It.IsAny<string>())).ReturnsAsync(() => stored);
+        repo.Setup(r => r.TryPinIdentityObjectIdAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .ReturnsAsync((string _, string tid, string oid) =>
+            {
+                if (stored != null && !stored.IsObjectIdPinned && stored.TenantId == tid)
+                    stored.ObjectId = oid;
+                return stored;
+            });
+        repo.Setup(r => r.UpsertIdentityBindingAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string?>(), It.IsAny<string>()))
+            .ReturnsAsync((string upn, string tid, string? oid, string by) =>
+            {
+                stored = new AdminIdentityBinding { Upn = upn, TenantId = tid, ObjectId = oid ?? string.Empty, BoundBy = by };
+                return true;
+            });
+        var svc = new AdminIdentityBindingService(
+            repo.Object, new MemoryCache(new MemoryCacheOptions()), NullLogger<AdminIdentityBindingService>.Instance);
+        return (svc, repo);
+    }
+
+    private static AdminIdentityBinding Binding(string tenantId, string objectId = "") =>
+        new() { Upn = Upn, TenantId = tenantId, ObjectId = objectId };
+
+    private static AdminIdentity Caller(string tenantId = HomeTenant, string oid = Oid) => new(Upn, tenantId, oid);
+
+    // ── Verdict matrix ────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task NullIdentity_IsNeverBound_AndReadsNothing()
+    {
+        var (svc, repo) = Build(Binding(HomeTenant, Oid));
+        Assert.False(await svc.IsBoundAsync(null));
+        repo.Verify(r => r.GetIdentityBindingAsync(It.IsAny<string>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task NoBindingRow_IsNotBound()
+    {
+        // A legacy role row without a binding is inert — fail-closed, never "bind whoever shows up first".
+        var (svc, _) = Build(stored: null);
+        Assert.False(await svc.IsBoundAsync(Caller()));
+    }
+
+    [Fact]
+    public async Task ForeignTenant_WithMatchingUpn_IsNotBound()
+    {
+        // The finding's primary exploit: same UPN string minted by another Entra tenant (domain re-registered,
+        // or a lookalike verified elsewhere). The tid is the immutable discriminator.
+        var (svc, repo) = Build(Binding(HomeTenant, Oid));
+        Assert.False(await svc.IsBoundAsync(Caller(tenantId: ForeignTenant)));
+        // And it must not pin anything onto the real admin's binding.
+        repo.Verify(r => r.TryPinIdentityObjectIdAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task ForeignTenant_AgainstUnpinnedBinding_DoesNotPin()
+    {
+        // Unpinned binding + foreign-tenant token: tenant mismatch is checked BEFORE the pin, so the
+        // attacker cannot "claim" the object-id slot of an admin who has not signed in yet.
+        var (svc, repo) = Build(Binding(HomeTenant));
+        Assert.False(await svc.IsBoundAsync(Caller(tenantId: ForeignTenant)));
+        repo.Verify(r => r.TryPinIdentityObjectIdAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task PinnedBinding_MatchingTidAndOid_IsBound()
+    {
+        var (svc, _) = Build(Binding(HomeTenant, Oid));
+        Assert.True(await svc.IsBoundAsync(Caller()));
+    }
+
+    [Fact]
+    public async Task PinnedBinding_SameTenantDifferentOid_IsNotBound()
+    {
+        // UPN recycling inside the home tenant: a User Administrator re-assigns the UPN to another account.
+        // Same tid, new oid — refused until an operator explicitly rebinds.
+        var (svc, _) = Build(Binding(HomeTenant, Oid));
+        Assert.False(await svc.IsBoundAsync(Caller(oid: OtherOid)));
+    }
+
+    [Fact]
+    public async Task UnpinnedBinding_FirstSignInFromHomeTenant_PinsAndIsBound_ThenEnforced()
+    {
+        var (svc, repo) = Build(Binding(HomeTenant));
+
+        Assert.True(await svc.IsBoundAsync(Caller()));
+        repo.Verify(r => r.TryPinIdentityObjectIdAsync(Upn, HomeTenant, Oid), Times.Once);
+
+        // Pinned now: the same account stays bound, any other account in the same tenant is refused.
+        Assert.True(await svc.IsBoundAsync(Caller()));
+        Assert.False(await svc.IsBoundAsync(Caller(oid: OtherOid)));
+        // The pin happened exactly once — later calls verify against the stored (cached) binding.
+        repo.Verify(r => r.TryPinIdentityObjectIdAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Fact]
+    public async Task ConcurrentPin_LostRace_VerifiesAgainstStoredWinner()
+    {
+        // Two accounts in the home tenant race the first sign-in; the repository's conditional update lets
+        // exactly one win. The loser must be judged against what was STORED, never against its own intent.
+        var (svc, repo) = Build(Binding(HomeTenant));
+        repo.Setup(r => r.TryPinIdentityObjectIdAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .ReturnsAsync(Binding(HomeTenant, OtherOid)); // someone else won
+
+        Assert.False(await svc.IsBoundAsync(Caller()));
+    }
+
+    [Fact]
+    public async Task PinResult_Null_MeansBindingVanished_IsNotBound()
+    {
+        // Binding removed between the cached read and the pin (operator DELETE racing the sign-in).
+        var (svc, repo) = Build(Binding(HomeTenant));
+        repo.Setup(r => r.TryPinIdentityObjectIdAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .ReturnsAsync((AdminIdentityBinding?)null);
+
+        Assert.False(await svc.IsBoundAsync(Caller()));
+    }
+
+    [Fact]
+    public async Task Verdict_IsCached_ButPinInvalidates()
+    {
+        var (svc, repo) = Build(Binding(HomeTenant, Oid));
+        Assert.True(await svc.IsBoundAsync(Caller()));
+        Assert.True(await svc.IsBoundAsync(Caller()));
+        repo.Verify(r => r.GetIdentityBindingAsync(It.IsAny<string>()), Times.Once);
+    }
+
+    [Fact]
+    public async Task Rebind_InvalidatesCache_SoNewTenantTakesEffectImmediately()
+    {
+        var (svc, _) = Build(Binding(HomeTenant, Oid));
+        Assert.True(await svc.IsBoundAsync(Caller()));
+
+        await svc.RebindAsync(Upn, ForeignTenant, OtherOid, "ga@vendor.example");
+
+        Assert.False(await svc.IsBoundAsync(Caller()));
+        Assert.True(await svc.IsBoundAsync(Caller(tenantId: ForeignTenant, oid: OtherOid)));
+    }
+
+    // ── Grant-time binding (EnsureBoundAsync) ─────────────────────────────────────
+
+    [Fact]
+    public async Task Ensure_NoExistingBinding_CreatesIt()
+    {
+        var (svc, repo) = Build(stored: null);
+        var b = await svc.EnsureBoundAsync(Upn, HomeTenant, null, "ga@vendor.example");
+        Assert.Equal(HomeTenant, b.TenantId);
+        Assert.False(b.IsObjectIdPinned);
+        repo.Verify(r => r.UpsertIdentityBindingAsync(Upn, HomeTenant, null, "ga@vendor.example"), Times.Once);
+    }
+
+    [Fact]
+    public async Task Ensure_SameTenant_KeepsExistingPin_NoWrite()
+    {
+        // A second grant (another managed tenant / a group) for an already-bound UPN is a no-op on the binding.
+        var (svc, repo) = Build(Binding(HomeTenant, Oid));
+        var b = await svc.EnsureBoundAsync(Upn, HomeTenant, null, "ga@vendor.example");
+        Assert.Equal(Oid, b.ObjectId);
+        repo.Verify(r => r.UpsertIdentityBindingAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string?>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task Ensure_SameTenant_UnpinnedThenObjectIdSupplied_Upgrades()
+    {
+        var (svc, repo) = Build(Binding(HomeTenant));
+        var b = await svc.EnsureBoundAsync(Upn, HomeTenant, Oid, "ga@vendor.example");
+        Assert.Equal(Oid, b.ObjectId);
+        repo.Verify(r => r.UpsertIdentityBindingAsync(Upn, HomeTenant, Oid, "ga@vendor.example"), Times.Once);
+    }
+
+    [Fact]
+    public async Task Ensure_DifferentTenant_Conflicts_NeverRehomes()
+    {
+        // A grant must not be a covert rebind: moving a UPN to another tenant is an explicit PUT.
+        var (svc, repo) = Build(Binding(HomeTenant, Oid));
+        await Assert.ThrowsAsync<IdentityBindingConflictException>(
+            () => svc.EnsureBoundAsync(Upn, ForeignTenant, null, "ga@vendor.example"));
+        repo.Verify(r => r.UpsertIdentityBindingAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string?>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task Ensure_DifferentPinnedObjectId_Conflicts()
+    {
+        var (svc, _) = Build(Binding(HomeTenant, Oid));
+        await Assert.ThrowsAsync<IdentityBindingConflictException>(
+            () => svc.EnsureBoundAsync(Upn, HomeTenant, OtherOid, "ga@vendor.example"));
+    }
+
+    [Fact]
+    public async Task Ensure_NormalizesCase()
+    {
+        var (svc, repo) = Build(stored: null);
+        await svc.EnsureBoundAsync("Admin@Vendor.Example", HomeTenant.ToUpperInvariant(), Oid.ToUpperInvariant(), "ga@vendor.example");
+        repo.Verify(r => r.UpsertIdentityBindingAsync(Upn, HomeTenant, Oid, "ga@vendor.example"), Times.Once);
+    }
+
+    // ── AdminIdentity construction ────────────────────────────────────────────────
+
+    [Theory]
+    [InlineData(null, HomeTenant, Oid)]
+    [InlineData(Upn, "", Oid)]
+    [InlineData(Upn, HomeTenant, "  ")]
+    public void AdminIdentity_Create_RequiresAllThree(string? upn, string? tid, string? oid)
+        => Assert.Null(AdminIdentity.Create(upn, tid, oid));
+
+    [Fact]
+    public void AdminIdentity_Create_Lowercases()
+    {
+        var id = AdminIdentity.Create("Admin@Vendor.Example", HomeTenant.ToUpperInvariant(), Oid.ToUpperInvariant());
+        Assert.Equal(new AdminIdentity(Upn, HomeTenant, Oid), id);
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/AdminIdentityResolverTests.cs

@@ -0,0 +1,104 @@
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.DataAccess;
+using AutopilotMonitor.Shared.Models;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Pins <see cref="AdminIdentityResolver"/> — what makes granting a cross-tenant role "type the UPN":
+/// sign-in history first (tid + oid, both from validated tokens), then UPN domain → onboarded tenant
+/// (tid only, oid pinned on first sign-in), and NO answer when the history is ambiguous (same UPN under
+/// two tenants — exactly the situation the binding exists for) or the domain is unknown.
+/// </summary>
+public class AdminIdentityResolverTests
+{
+    private const string Upn = "msp@partner.example";
+    private const string TenantA = "11111111-1111-1111-1111-111111111111";
+    private const string TenantB = "22222222-2222-2222-2222-222222222222";
+    private const string OidOld = "aaaaaaaa-1111-1111-1111-aaaaaaaaaaaa";
+    private const string OidNew = "bbbbbbbb-2222-2222-2222-bbbbbbbbbbbb";
+
+    private static AdminIdentityResolver Build(
+        IEnumerable<UserSignInIdentity>? signIns = null,
+        params (string TenantId, string Domain)[] tenants)
+    {
+        var metrics = new Mock<IMetricsRepository>();
+        metrics.Setup(m => m.GetSignInIdentitiesByUpnAsync(It.IsAny<string>()))
+            .ReturnsAsync((signIns ?? Array.Empty<UserSignInIdentity>()).ToList());
+
+        var configRepo = new Mock<IConfigRepository>();
+        configRepo.Setup(r => r.GetAllTenantConfigurationsAsync())
+            .ReturnsAsync(tenants.Select(t => new TenantConfiguration { TenantId = t.TenantId, DomainName = t.Domain }).ToList());
+        var configService = new TenantConfigurationService(
+            configRepo.Object, NullLogger<TenantConfigurationService>.Instance, new MemoryCache(new MemoryCacheOptions()));
+
+        return new AdminIdentityResolver(metrics.Object, configService, NullLogger<AdminIdentityResolver>.Instance);
+    }
+
+    private static UserSignInIdentity SignIn(string tid, string oid, int daysAgo) => new()
+    {
+        TenantId = tid, ObjectId = oid, LastLoginAt = DateTime.UtcNow.AddDays(-daysAgo), LoginCount = 1,
+    };
+
+    [Fact]
+    public async Task SignInHistory_SingleTenant_ResolvesTidAndOid()
+    {
+        var r = await Build(new[] { SignIn(TenantA, OidOld, 3) }).ResolveAsync("MSP@Partner.Example");
+        Assert.NotNull(r);
+        Assert.Equal(TenantA, r!.TenantId);
+        Assert.Equal(OidOld, r.ObjectId);
+        Assert.Equal(ResolvedAdminIdentity.SourceSignIn, r.Source);
+    }
+
+    [Fact]
+    public async Task SignInHistory_SameTenantTwoOids_TakesMostRecent()
+    {
+        // Account re-created in the same tenant: the newer oid is the one that will sign in next.
+        var r = await Build(new[] { SignIn(TenantA, OidOld, 30), SignIn(TenantA, OidNew, 1) }).ResolveAsync(Upn);
+        Assert.Equal(OidNew, r!.ObjectId);
+    }
+
+    [Fact]
+    public async Task SignInHistory_TwoTenants_IsAmbiguous_NotResolved_EvenIfDomainMatches()
+    {
+        // The same UPN string seen under two tenants is the attack shape; never auto-pick, even when the
+        // domain fallback would have an answer.
+        var r = await Build(new[] { SignIn(TenantA, OidOld, 3), SignIn(TenantB, OidNew, 1) }, (TenantA, "partner.example"))
+            .ResolveAsync(Upn);
+        Assert.Null(r);
+    }
+
+    [Fact]
+    public async Task NoSignIns_DomainOfOnboardedTenant_ResolvesTidOnly()
+    {
+        var r = await Build(null, (TenantA, "Partner.Example"), (TenantB, "other.example")).ResolveAsync(Upn);
+        Assert.NotNull(r);
+        Assert.Equal(TenantA, r!.TenantId);
+        Assert.Null(r.ObjectId);
+        Assert.Equal(ResolvedAdminIdentity.SourceDomain, r.Source);
+    }
+
+    [Fact]
+    public async Task NoSignIns_TwoTenantsClaimTheDomain_NotResolved()
+    {
+        var r = await Build(null, (TenantA, "partner.example"), (TenantB, "partner.example")).ResolveAsync(Upn);
+        Assert.Null(r);
+    }
+
+    [Fact]
+    public async Task NoSignIns_UnknownDomain_NotResolved()
+    {
+        var r = await Build(null, (TenantA, "other.example")).ResolveAsync(Upn);
+        Assert.Null(r);
+    }
+
+    [Theory]
+    [InlineData("nodomain")]
+    [InlineData("trailing@")]
+    public async Task MalformedUpn_NotResolved(string upn)
+        => Assert.Null(await Build(null, (TenantA, "partner.example")).ResolveAsync(upn));
+}

src/Backend/AutopilotMonitor.Functions.Tests/AnalyzeRuleRelatedDocsUrlTests.cs

@@ -0,0 +1,92 @@
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.DataAccess;
+using AutopilotMonitor.Shared.Models;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Stored-XSS guard for analyze-rule relatedDocs: the author-controlled URL is rendered as
+/// an anchor href for every viewer (including cross-tenant admins), so only absolute
+/// http(s) URLs may persist. Create and Update both reject anything else with an
+/// <see cref="ArgumentException"/> (400), and drop blank entries silently.
+/// </summary>
+public class AnalyzeRuleRelatedDocsUrlTests
+{
+    private const string TenantId = "a1b2c3d4-e5f6-7890-abcd-ef1234567890";
+
+    [Theory]
+    [InlineData("https://learn.microsoft.com/x", true)]
+    [InlineData("http://example.com/", true)]
+    [InlineData("  https://example.com/a?b=c#d ", true)]
+    [InlineData("javascript:alert(1)", false)]
+    [InlineData("JavaScript:fetch('https://example.com/'+localStorage.token)", false)]
+    [InlineData("data:text/html,<script>alert(1)</script>", false)]
+    [InlineData("vbscript:msgbox(1)", false)]
+    [InlineData("file:///etc/passwd", false)]
+    [InlineData("/relative/path", false)]
+    [InlineData("example.com", false)]
+    [InlineData("", false)]
+    [InlineData(null, false)]
+    public void IsAbsoluteHttpUrl_allows_only_absolute_http_and_https(string? url, bool expected)
+    {
+        Assert.Equal(expected, AnalyzeRuleService.IsAbsoluteHttpUrl(url));
+    }
+
+    [Fact]
+    public async Task CreateRuleAsync_rejects_javascript_url_and_never_persists()
+    {
+        var repo = new Mock<IRuleRepository>(MockBehavior.Strict);
+        repo.Setup(r => r.AnalyzeRuleExistsAsync(It.IsAny<string>(), It.IsAny<string>())).ReturnsAsync(false);
+        var service = new AnalyzeRuleService(repo.Object, NullLogger<AnalyzeRuleService>.Instance);
+
+        var rule = MakeRule(new RelatedDoc { Title = "Microsoft Docs: fix this error", Url = "javascript:alert(1)" });
+
+        var ex = await Assert.ThrowsAsync<ArgumentException>(() => service.CreateRuleAsync(TenantId, rule));
+        Assert.Contains("javascript:alert(1)", ex.Message);
+        repo.Verify(r => r.StoreAnalyzeRuleAsync(It.IsAny<AnalyzeRule>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task UpdateRuleAsync_rejects_data_url_for_custom_rule()
+    {
+        var repo = new Mock<IRuleRepository>(MockBehavior.Strict);
+        var service = new AnalyzeRuleService(repo.Object, NullLogger<AnalyzeRuleService>.Instance);
+
+        var rule = MakeRule(new RelatedDoc { Title = "Docs", Url = "data:text/html,<script>alert(1)</script>" });
+
+        await Assert.ThrowsAsync<ArgumentException>(() => service.UpdateRuleAsync(TenantId, rule));
+        repo.Verify(r => r.StoreAnalyzeRuleAsync(It.IsAny<AnalyzeRule>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task CreateRuleAsync_keeps_https_docs_and_drops_blank_entries()
+    {
+        AnalyzeRule? stored = null;
+        var repo = new Mock<IRuleRepository>(MockBehavior.Strict);
+        repo.Setup(r => r.AnalyzeRuleExistsAsync(It.IsAny<string>(), It.IsAny<string>())).ReturnsAsync(false);
+        repo.Setup(r => r.StoreAnalyzeRuleAsync(It.IsAny<AnalyzeRule>(), TenantId))
+            .Callback<AnalyzeRule, string>((r, _) => stored = r)
+            .ReturnsAsync(true);
+        var service = new AnalyzeRuleService(repo.Object, NullLogger<AnalyzeRuleService>.Instance);
+
+        var rule = MakeRule(
+            new RelatedDoc { Title = "Good", Url = "https://learn.microsoft.com/x" },
+            new RelatedDoc { Title = "", Url = "" },          // editor "+ Add Link" default, untouched
+            new RelatedDoc { Title = "Blank", Url = "   " });
+
+        Assert.True(await service.CreateRuleAsync(TenantId, rule));
+        Assert.NotNull(stored);
+        var doc = Assert.Single(stored!.RelatedDocs);
+        Assert.Equal("https://learn.microsoft.com/x", doc.Url);
+    }
+
+    private static AnalyzeRule MakeRule(params RelatedDoc[] docs) => new()
+    {
+        RuleId = "TENANT-DOCS-URL-001",
+        IsBuiltIn = false,
+        IsCommunity = false,
+        RelatedDocs = docs.ToList(),
+    };
+}

src/Backend/AutopilotMonitor.Functions.Tests/AuthFunctionSideEffectTests.cs

@@ -1,4 +1,5 @@
 using AutopilotMonitor.Functions.Functions.Infrastructure;
+using AutopilotMonitor.Functions.Security;
 using AutopilotMonitor.Functions.Services;
 using AutopilotMonitor.Shared.DataAccess;
 using AutopilotMonitor.Shared.Models;
@@ -39,16 +40,18 @@ public class AuthFunctionSideEffectTests
             configRepo, Mock.Of<ILogger<TenantConfigurationService>>(), cache)
         { CallBase = false };
 
+        var bindings = new StubAdminIdentityBindingService(bound: true);
         var globalAdminMock = new Mock<GlobalAdminService>(
-            adminRepo, cache, Mock.Of<ILogger<GlobalAdminService>>())
+            adminRepo, bindings, cache, Mock.Of<ILogger<GlobalAdminService>>())
         { CallBase = false };
 
         var delegatedAdminMock = new Mock<DelegatedAdminService>(
             adminRepo,
+            bindings,
             new StubTenantEntitlementService(AutopilotMonitor.Functions.Security.TenantEdition.Pro),
             cache, Mock.Of<ILogger<DelegatedAdminService>>())
         { CallBase = false };
-        delegatedAdminMock.Setup(x => x.GetScopeAsync(It.IsAny<string>(), It.IsAny<string?>()))
+        delegatedAdminMock.Setup(x => x.GetScopeAsync(It.IsAny<AdminIdentity?>()))
             .ReturnsAsync(DelegatedScope.Empty);
 
         _tenantAdminsMock = new Mock<TenantAdminsService>(
@@ -93,7 +96,9 @@ public class AuthFunctionSideEffectTests
             _autoApproveEnqueuerMock.Object,
             new AutopilotMonitor.Functions.Security.EntraAppRegistry(
                 new Microsoft.Extensions.Configuration.ConfigurationBuilder().Build(),
-                Mock.Of<ILogger<AutopilotMonitor.Functions.Security.EntraAppRegistry>>()));
+                Mock.Of<ILogger<AutopilotMonitor.Functions.Security.EntraAppRegistry>>()),
+            new Mock<AdminIdentityResolver>(
+                _metricsRepoMock.Object, _tenantConfigMock.Object, Mock.Of<ILogger<AdminIdentityResolver>>()) { CallBase = false }.Object);
 
         // Default: all fire-and-forget calls succeed
         _tenantConfigMock

src/Backend/AutopilotMonitor.Functions.Tests/AzureQueueImeMsiArchiveProducerTests.cs

@@ -35,7 +35,7 @@ public class AzureQueueImeMsiArchiveProducerTests
         Assert.Equal(2, sentBodies.Count);
         var roundTripped = JsonConvert.DeserializeObject<ImeMsiArchiveEnvelope>(sentBodies[0])!;
         Assert.Equal(Version, roundTripped.Version);
-        Assert.Equal(ImeMsiArchiver.CanonicalMsiUrl, roundTripped.MsiDownloadUrl);
+        Assert.Equal(ImeMsiArchiver.FallbackMsiUrls[1], roundTripped.MsiDownloadUrl);
         Assert.Equal("11111111-1111-1111-1111-111111111111", roundTripped.TenantId);
         // Queue existence is ensured once, then latched — not re-checked per message.
         queue.Verify(q => q.CreateIfNotExistsAsync(
@@ -92,7 +92,7 @@ public class AzureQueueImeMsiArchiveProducerTests
     private static ImeMsiArchiveEnvelope Envelope() => new()
     {
         Version = Version,
-        MsiDownloadUrl = ImeMsiArchiver.CanonicalMsiUrl,
+        MsiDownloadUrl = ImeMsiArchiver.FallbackMsiUrls[1],
         MsiMatchedBy = "productVersion",
         TenantId = "11111111-1111-1111-1111-111111111111",
         SessionId = "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",

src/Backend/AutopilotMonitor.Functions.Tests/BootstrapAuthDisabledTenantTests.cs

@@ -1,4 +1,4 @@
-using System.Net;
+using System.Net;
 using AutopilotMonitor.Functions.Security;
 using AutopilotMonitor.Functions.Services;
 using AutopilotMonitor.Shared.DataAccess;
@@ -99,8 +99,9 @@ public sealed class BootstrapAuthDisabledTenantTests
     {
         // Sanity: a non-disabled tenant DOES reach the bootstrap branch (which will then
         // run its own validation against _bootstrapSessionService). With _bootstrapSessionService
-        // null in this test, the bootstrap branch falls through to the cert path — proving
-        // that the §0 gate did NOT block.
+        // null and no request URL (= not a /api/bootstrap/* route, where that combination is
+        // rejected fail-closed — see BootstrapRouteFailClosedTests), the branch falls through to
+        // the platform-cert path — proving that the §0 gate did NOT block.
         var enabled = TenantConfiguration.CreateDefault(TenantId);
         enabled.Disabled = false;
         enabled.ValidateAutopilotDevice = false;

src/Backend/AutopilotMonitor.Functions.Tests/BootstrapRouteFailClosedTests.cs

@@ -0,0 +1,161 @@
+using System.Net;
+using AutopilotMonitor.Functions.Security;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.DataAccess;
+using AutopilotMonitor.Shared.Models;
+using Microsoft.Azure.Functions.Worker.Http;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging;
+using Moq;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Bootstrap routes (<c>/api/bootstrap/*</c>) are excluded from the platform's TLS client-cert
+/// requirement, so nothing on those paths proves an mTLS handshake ever happened. The bootstrap
+/// token must therefore be the ONLY credential accepted there — a request that reaches the
+/// certificate stage on a bootstrap route would authenticate from header bytes alone (a public
+/// certificate is replayable without its private key). Live probe 2026-08-29: an empty
+/// <c>X-Bootstrap-Token</c> passed the function gate, skipped the token branch and had a
+/// client-supplied certificate header parsed. These tests pin the fail-closed behaviour.
+/// </summary>
+public sealed class BootstrapRouteFailClosedTests
+{
+    private const string TenantId = "aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee";
+    private const string BootstrapRoute = "https://example.invalid/api/bootstrap/config";
+    private const string AgentRoute = "https://example.invalid/api/agent/telemetry";
+
+    // A well-formed DER certificate is not needed: what matters is whether the certificate stage
+    // ran at all, and the "No certificate provided" vs. parse-error details tell the two apart.
+    private const string JunkCertBase64 = "QUJD";
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    public async Task BootstrapRoute_TokenMissingOrEmpty_Rejected401_BeforeCertificateStage(string? token)
+    {
+        var sut = BuildValidator(bootstrapService: null);
+        var req = BuildRequest(BootstrapRoute, token, ("X-ARR-ClientCert", JunkCertBase64));
+
+        var result = await sut.ValidateRequestAsync(req, TenantId);
+
+        Assert.False(result.IsValid);
+        Assert.Equal(HttpStatusCode.Unauthorized, result.StatusCode);
+        Assert.Equal("X-Bootstrap-Token header is required", result.ErrorMessage);
+    }
+
+    [Fact]
+    public async Task BootstrapRoute_ClientSuppliedCertificateHeader_NeverParsed()
+    {
+        var sut = BuildValidator(bootstrapService: null);
+        var req = BuildRequest(BootstrapRoute, token: "", ("X-Client-Certificate", JunkCertBase64));
+
+        var result = await sut.ValidateRequestAsync(req, TenantId);
+
+        Assert.Equal(HttpStatusCode.Unauthorized, result.StatusCode);
+        Assert.Equal("X-Bootstrap-Token header is required", result.ErrorMessage);
+        Assert.DoesNotContain("certificate", result.ErrorMessage, StringComparison.OrdinalIgnoreCase);
+    }
+
+    [Fact]
+    public async Task AgentRoute_ClientCertificateHeader_IsIgnored()
+    {
+        // The removed X-Client-Certificate fallback: on a platform-enforced route the only
+        // certificate source is X-ARR-ClientCert. A client-writable header must read as "no cert".
+        var sut = BuildValidator(bootstrapService: null);
+        var req = BuildRequest(AgentRoute, token: null, ("X-Client-Certificate", JunkCertBase64));
+
+        var result = await sut.ValidateRequestAsync(req, TenantId);
+
+        Assert.False(result.IsValid);
+        Assert.Equal(HttpStatusCode.Unauthorized, result.StatusCode);
+        Assert.Equal("Invalid or missing client certificate", result.ErrorMessage);
+        Assert.Equal("No certificate provided", result.Details);
+    }
+
+    [Fact]
+    public async Task AgentRoute_ArrClientCertHeader_ReachesCertificateStage()
+    {
+        // Control: the platform-set header is still the one consulted (junk bytes → parse error,
+        // proving the certificate stage ran on the supplied value).
+        var sut = BuildValidator(bootstrapService: null);
+        var req = BuildRequest(AgentRoute, token: null, ("X-ARR-ClientCert", JunkCertBase64));
+
+        var result = await sut.ValidateRequestAsync(req, TenantId);
+
+        Assert.Equal(HttpStatusCode.Unauthorized, result.StatusCode);
+        Assert.Equal("Invalid or missing client certificate", result.ErrorMessage);
+        Assert.NotEqual("No certificate provided", result.Details);
+    }
+
+    [Fact]
+    public void GetBootstrapToken_TreatsEmptyAsAbsent()
+    {
+        Assert.Null(SecurityValidator.GetBootstrapToken(BuildRequest(BootstrapRoute, token: "")));
+        Assert.Null(SecurityValidator.GetBootstrapToken(BuildRequest(BootstrapRoute, token: null)));
+        Assert.Equal("abc", SecurityValidator.GetBootstrapToken(BuildRequest(BootstrapRoute, token: "abc")));
+    }
+
+    [Theory]
+    [InlineData("https://example.invalid/api/bootstrap/config", true)]
+    [InlineData("https://example.invalid/API/Bootstrap/register-session", true)]
+    [InlineData("https://example.invalid/api/bootstrapx/config", false)]
+    [InlineData("https://example.invalid/api/agent/telemetry", false)]
+    public void IsBootstrapRoute_MatchesPlatformExclusionPrefix(string url, bool expected)
+    {
+        Assert.Equal(expected, SecurityValidator.IsBootstrapRoute(BuildRequest(url, token: null)));
+    }
+
+    // ---------------------------------------------------------------- harness
+
+    private static SecurityValidator BuildValidator(BootstrapSessionService? bootstrapService)
+    {
+        var configRepo = Mock.Of<IConfigRepository>();
+        var cache = new MemoryCache(new MemoryCacheOptions());
+
+        // AllowInsecureAgentRequests clears the "at least one device validator" gate so agent-route
+        // requests reach the certificate stage — the stage these tests reason about.
+        var config = TenantConfiguration.CreateDefault(TenantId);
+        config.AllowInsecureAgentRequests = true;
+
+        var configServiceMock = new Mock<TenantConfigurationService>(
+            configRepo, Mock.Of<ILogger<TenantConfigurationService>>(), cache)
+        { CallBase = false };
+        configServiceMock
+            .Setup(x => x.TryGetConfigurationAsync(It.IsAny<string>()))
+            .ReturnsAsync((config, true));
+
+        var adminConfigServiceMock = new Mock<AdminConfigurationService>(
+            configRepo, Mock.Of<ILogger<AdminConfigurationService>>(), cache)
+        { CallBase = false };
+        adminConfigServiceMock
+            .Setup(x => x.GetConfigurationAsync())
+            .ReturnsAsync(new AdminConfiguration());
+
+        return new SecurityValidator(
+            configService: configServiceMock.Object,
+            adminConfigService: adminConfigServiceMock.Object,
+            rateLimitService: new RateLimitService(cache, Mock.Of<ILogger<RateLimitService>>()),
+            autopilotDeviceValidator: null!,
+            corporateIdentifierValidator: null!,
+            logger: Mock.Of<ILogger>(),
+            bootstrapSessionService: bootstrapService,
+            deviceAssociationValidator: null);
+    }
+
+    private static HttpRequestData BuildRequest(string url, string? token, params (string Name, string Value)[] extraHeaders)
+    {
+        var contextMock = new Mock<Microsoft.Azure.Functions.Worker.FunctionContext>();
+        contextMock.SetupGet(c => c.Items).Returns(new Dictionary<object, object>());
+        var reqMock = new Mock<HttpRequestData>(contextMock.Object);
+
+        var headers = new HttpHeadersCollection();
+        if (token != null) headers.Add("X-Bootstrap-Token", token);
+        foreach (var (name, value) in extraHeaders) headers.Add(name, value);
+
+        reqMock.SetupGet(r => r.Headers).Returns(headers);
+        reqMock.SetupGet(r => r.Url).Returns(new Uri(url));
+        return reqMock.Object;
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/CertTenantBindingTests.cs

@@ -13,18 +13,21 @@ using Moq;
 namespace AutopilotMonitor.Functions.Tests;
 
 /// <summary>
-/// CERT-TENANT-BINDING-SHADOW — stage 1 coverage.
+/// CERT-TENANT-BINDING — enforced since 2026-08-25.
 ///
 /// The agent authenticates with the Intune MDM device certificate, whose chain is pinned to
 /// Microsoft's Intune roots. Those roots are shared by every Intune tenant, so a valid chain alone
 /// does not prove the caller belongs to the tenant it claims. The CA stamps the Entra tenant id
 /// into OID 1.2.840.113556.5.14, which lets the backend bind the two.
 ///
-/// These tests pin three things:
+/// These tests pin four things:
 ///   - the tenant id is actually extracted from a REAL field certificate (not a synthetic fixture),
+///     because if Microsoft ever changes that stamp, enforcement locks out the whole fleet,
 ///   - the pure comparison covers every outcome the telemetry can report,
-///   - shadow mode observes without deciding: a cross-tenant certificate must still pass the
-///     certificate stage in stage 1, or we would be enforcing before we measured.
+///   - the enforcement rule rejects Mismatch and ONLY Mismatch — ExtensionMissing is tolerated on
+///     purpose, and that tolerance has its own test so removing it has to be a decision,
+///   - a rejected request still carries its telemetry and does not leak the certificate's tenant
+///     back to the caller.
 /// </summary>
 public class CertTenantBindingTests
 {
@@ -200,13 +203,58 @@ public class CertTenantBindingTests
         Assert.False(CertTenantBinding.WouldRejectUnderEnforcement(outcome));
     }
 
-    // ---------------------------------------------------------------- shadow mode
+    // ---------------------------------------------------------------- enforcement rule
 
     [Fact]
-    public async Task ValidateRequestAsync_ForeignTenantCert_IsObservedButNotRejected()
+    public void Rejects_OnlyMismatch()
     {
-        // Stage 1 contract: a cross-tenant certificate is logged and still passes the certificate
-        // stage. If this test ever fails, enforcement was switched on without the telemetry review.
+        // Mismatch is the only outcome that is evidence of a foreign certificate. The rest mean
+        // "cannot tell", and rejecting on those would cost legitimate devices their enrollment for
+        // something outside their control.
+        Assert.True(CertTenantBinding.Rejects(CertTenantBinding.Outcome.Mismatch));
+
+        Assert.False(CertTenantBinding.Rejects(CertTenantBinding.Outcome.Match));
+        Assert.False(CertTenantBinding.Rejects(CertTenantBinding.Outcome.ExtensionMissing));
+        Assert.False(CertTenantBinding.Rejects(CertTenantBinding.Outcome.Unparseable));
+        Assert.False(CertTenantBinding.Rejects(CertTenantBinding.Outcome.RequestTenantNotAGuid));
+    }
+
+    [Fact]
+    public void Rejects_ExtensionMissingIsDeliberatelyTolerated()
+    {
+        // Pinned on its own because it is the one that is expected to tighten later: certificates
+        // predating the extension, or a sovereign-cloud CA, must not be locked out today. Changing
+        // this is a decision, and this test is where that decision has to be made explicitly.
+        Assert.False(CertTenantBinding.Rejects(CertTenantBinding.Outcome.ExtensionMissing));
+    }
+
+    [Fact]
+    public void Rejects_AgreesWithTheTelemetryField()
+    {
+        // WouldRejectUnderEnforcement is what the log line reports. If the two ever diverge, the
+        // telemetry stops describing what actually happened.
+        foreach (var outcome in new[]
+                 {
+                     CertTenantBinding.Outcome.Match,
+                     CertTenantBinding.Outcome.Mismatch,
+                     CertTenantBinding.Outcome.ExtensionMissing,
+                     CertTenantBinding.Outcome.Unparseable,
+                     CertTenantBinding.Outcome.RequestTenantNotAGuid,
+                 })
+        {
+            Assert.Equal(CertTenantBinding.Rejects(outcome),
+                         CertTenantBinding.WouldRejectUnderEnforcement(outcome));
+        }
+    }
+
+    // ---------------------------------------------------------------- end-to-end
+
+    [Fact]
+    public async Task ValidateRequestAsync_ForeignTenantCert_IsRejected()
+    {
+        // The attack this whole feature exists for: a valid Intune certificate from the attacker's
+        // own tenant, replayed against a victim tenant whose device serial they know. Serials are
+        // printed on the chassis, so before this gate that was the entire barrier.
         var logger = new CapturingLogger();
         var validator = BuildValidator(logger);
 
@@ -214,16 +262,40 @@ public class CertTenantBindingTests
             BuildRequestWithCert(SampleCertBase64()),
             tenantId: "aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee");
 
-        // Deliberately accepted: stage 1 measures, it does not enforce. This assertion is the one
-        // that must be inverted (to a 403) when stage 2 turns enforcement on.
-        Assert.True(result.IsValid, $"Shadow mode changed the outcome: {result.ErrorMessage} / {result.Details}");
-        Assert.NotEqual(HttpStatusCode.Unauthorized, result.StatusCode);
+        Assert.False(result.IsValid);
+        Assert.Equal(HttpStatusCode.Forbidden, result.StatusCode);
+
+        // The response must not reveal which tenant the certificate actually belongs to.
+        Assert.DoesNotContain(SampleCertTenantId.ToString(), result.Details ?? "", StringComparison.OrdinalIgnoreCase);
+        Assert.DoesNotContain(SampleCertTenantId.ToString(), result.ErrorMessage ?? "", StringComparison.OrdinalIgnoreCase);
 
         var observed = Assert.Single(logger.Entries, e => e.Message.Contains("AgentCertTenantBinding"));
         Assert.Equal(LogLevel.Warning, observed.Level);
         Assert.Contains(CertTenantBinding.Outcome.Mismatch, observed.Message);
-        Assert.Contains("enforced=False", observed.Message);
+        Assert.Contains("enforced=True", observed.Message);
         Assert.Contains("wouldReject=True", observed.Message);
+
+        // The rejection must also land in the shared rejection log, so it shows up in the same KQL
+        // raster as every other reason a request was turned away.
+        Assert.Contains(logger.Entries, e => e.Message.Contains("AgentRequestRejected")
+                                             && e.Message.Contains("stage=certtenant"));
+    }
+
+    [Fact]
+    public async Task ValidateRequestAsync_MismatchStillStampsTheRequestRow()
+    {
+        // Enforcement must not cost us the telemetry: a blocked request is exactly the one an
+        // operator will go looking for afterwards.
+        var items = new Dictionary<object, object>();
+        var validator = BuildValidator(new CapturingLogger());
+
+        await validator.ValidateRequestAsync(
+            BuildRequestWithCert(SampleCertBase64(), items),
+            tenantId: "aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee");
+
+        Assert.Equal(
+            CertTenantBinding.Outcome.Mismatch,
+            Assert.Contains(CertTenantBinding.RequestItemKey, items));
     }
 
     [Fact]

src/Backend/AutopilotMonitor.Functions.Tests/CmTraceSkewTripwireTests.cs

@@ -119,6 +119,53 @@ public class CmTraceSkewTripwireTests
         Assert.Null(CmTraceSkewTripwire.Evaluate(scan));
     }
 
+    [Fact]
+    public void Silent_OnBacklogReplayBurstWhoseMedianLandsOnGrid()
+    {
+        // Field case 2026-08-28 (session d832560a): the agent died on auth failures, the relaunch
+        // re-tailed the IME log and uploaded 508 lines in one burst with a continuum of ages
+        // (46…733 min, quartiles 52 / 92 / 100) — median 91 min, i.e. 6×15 by pure chance.
+        // The other side was live. The per-sample grid-conformity guard must keep this silent.
+        var scan = MakeScan(imeDeltaMinutes: 0.1, otherDeltaMinutes: 0.1, imeSamples: 100, imeBatches: 80);
+        void AddRamp(double from, double to, int count)
+        {
+            for (int i = 0; i < count; i++)
+                scan.ImeDeltaMinutes.Add(from + i * (to - from) / count);
+        }
+        AddRamp(46.0, 88.0, 125);
+        AddRamp(88.0, 100.0, 250);
+        AddRamp(100.0, 733.0, 125);
+
+        var medianIme = scan.ImeDeltaMinutes.OrderBy(v => v).ElementAt(scan.ImeDeltaMinutes.Count / 2);
+        Assert.InRange(medianIme, 88.0, 92.0); // sanity: the median really does sit near 6×15
+
+        Assert.Null(CmTraceSkewTripwire.Evaluate(scan));
+        Assert.True(CmTraceSkewTripwire.ComputeGridConformantFraction(scan.ImeDeltaMinutes, 0.1) < 0.5);
+    }
+
+    [Fact]
+    public void Fires_OnTwoWriterErasBothOnGrid()
+    {
+        // e9753578 shape: one file mixing PDT (−420) and CEST (+120) lines relative to the agent
+        // zone. Every line is individually on the grid, so the conformity guard must NOT mask it.
+        var scan = MakeScan(imeDeltaMinutes: -420.0, otherDeltaMinutes: 0.0, imeSamples: 65);
+        for (int i = 0; i < 35; i++)
+            scan.ImeDeltaMinutes.Add(120.0);
+
+        var result = CmTraceSkewTripwire.Evaluate(scan);
+        Assert.NotNull(result);
+        Assert.Equal(-28, result!.GridSteps);
+        Assert.Equal(1.0, result.GridConformantFraction, 3);
+    }
+
+    [Fact]
+    public void GridConformantFraction_CountsZeroAndAnyMultiple()
+    {
+        var deltas = new List<double> { 0.5, 15.9, -30.1, 7.5, 37.5 }; // last two are off-grid
+        Assert.Equal(0.6, CmTraceSkewTripwire.ComputeGridConformantFraction(deltas, 0.0), 3);
+        Assert.Equal(0, CmTraceSkewTripwire.ComputeGridConformantFraction(new List<double>(), 0.0));
+    }
+
     // ── Bias suppression predicate ─────────────────────────────────────────
 
     [Fact]

src/Backend/AutopilotMonitor.Functions.Tests/CollectLogsQuickConfigOpsEventTests.cs

@@ -0,0 +1,97 @@
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Threading.Tasks;
+using AutopilotMonitor.Functions.Functions.Config;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Functions.Services.Notifications;
+using AutopilotMonitor.Shared.DataAccess;
+using AutopilotMonitor.Shared.Models;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// The targeted push signal: "someone clicked Collect Logs and switched on Hosted upload
+/// through the quick-config dialog" must land as its own ops event type, while every other
+/// enable path keeps the generic type — an alert rule filters by EventType only.
+/// </summary>
+public class CollectLogsQuickConfigOpsEventTests
+{
+    private static (OpsEventService Service, List<OpsEventEntry> Saved) Rig()
+    {
+        var saved = new List<OpsEventEntry>();
+        var opsRepo = new Mock<IOpsEventRepository>();
+        opsRepo.Setup(r => r.SaveOpsEventAsync(It.IsAny<OpsEventEntry>()))
+            .Callback<OpsEventEntry>(e => { lock (saved) saved.Add(e); })
+            .Returns(Task.CompletedTask);
+        var adminConfig = new Mock<AdminConfigurationService>(
+            Mock.Of<IConfigRepository>(), NullLogger<AdminConfigurationService>.Instance,
+            new MemoryCache(new MemoryCacheOptions())) { CallBase = false };
+        var alertDispatch = new OpsAlertDispatchService(
+            adminConfig.Object,
+            new TelegramNotificationService(new HttpClient(), Mock.Of<IConfigRepository>(),
+                NullLogger<TelegramNotificationService>.Instance),
+            new WebhookNotificationService(new HttpClient(), NullLogger<WebhookNotificationService>.Instance),
+            NullLogger<OpsAlertDispatchService>.Instance);
+        return (new OpsEventService(opsRepo.Object, NullLogger<OpsEventService>.Instance, alertDispatch), saved);
+    }
+
+    private static DiagnosticsUploadConfigChange EnableFlip() =>
+        DiagnosticsUploadConfigChange.Detect(
+            new TenantConfiguration { TenantId = "t1", DiagnosticsUploadMode = "Off" },
+            new TenantConfiguration { TenantId = "t1", DiagnosticsUploadMode = "OnFailure", DiagnosticsUploadDestination = "Hosted" })!;
+
+    [Theory]
+    [InlineData("collect-logs", UpdateTenantConfigurationFunction.CollectLogsSource)]
+    [InlineData("COLLECT-LOGS", UpdateTenantConfigurationFunction.CollectLogsSource)]
+    [InlineData(null, "portal-put")]
+    [InlineData("", "portal-put")]
+    [InlineData("something-else", "portal-put")]
+    public void ResolveWriteSource_only_honours_the_allow_listed_intent(string? intent, string expected)
+    {
+        Assert.Equal(expected, UpdateTenantConfigurationFunction.ResolveWriteSource(intent));
+    }
+
+    [Fact]
+    public async Task Quick_config_enable_lands_as_its_own_event_type()
+    {
+        var (service, saved) = Rig();
+
+        await service.RecordDiagnosticsUploadConfigChangedAsync(
+            "t1", "contoso.com", EnableFlip(), "admin@contoso.com", UpdateTenantConfigurationFunction.CollectLogsSource);
+
+        var evt = Assert.Single(saved);
+        Assert.Equal("CollectLogsQuickConfigEnabled", evt.EventType);
+        Assert.Equal(OpsEventCategory.Tenant, evt.Category);
+        Assert.Contains("admin@contoso.com", evt.Message);
+        Assert.Contains("Hosted", evt.Message);
+    }
+
+    [Theory]
+    [InlineData("portal-put")]
+    [InlineData("mcp-patch")]
+    public async Task Other_enable_paths_keep_the_generic_event_type(string source)
+    {
+        var (service, saved) = Rig();
+
+        await service.RecordDiagnosticsUploadConfigChangedAsync("t1", "contoso.com", EnableFlip(), "admin@contoso.com", source);
+
+        Assert.Equal("DiagnosticsUploadEnabled", Assert.Single(saved).EventType);
+    }
+
+    [Fact]
+    public async Task Quick_config_source_on_a_disable_is_the_generic_disabled_type()
+    {
+        var (service, saved) = Rig();
+        var disable = DiagnosticsUploadConfigChange.Detect(
+            new TenantConfiguration { TenantId = "t1", DiagnosticsUploadMode = "Always", DiagnosticsUploadDestination = "Hosted" },
+            new TenantConfiguration { TenantId = "t1", DiagnosticsUploadMode = "Off", DiagnosticsUploadDestination = "Hosted" })!;
+
+        await service.RecordDiagnosticsUploadConfigChangedAsync("t1", null, disable, "ga@x", UpdateTenantConfigurationFunction.CollectLogsSource);
+
+        Assert.Equal("DiagnosticsUploadDisabled", Assert.Single(saved).EventType);
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/CriticalTableBackupServiceTests.cs

@@ -47,7 +47,7 @@ public class CriticalTableBackupServiceTests
 
         Assert.Equal(BackupOutcome.Success, result.Outcome);
         Assert.True(store.ManifestWritten, "manifest must be written LAST");
-        Assert.Equal(18, result.Manifest.Tables.Count);   // critical-tables catalog count (incl. DelegatedAdmins + ConfigurationBackups + SessionAnnotations)
+        Assert.Equal(19, result.Manifest.Tables.Count);   // critical-tables catalog count (incl. DelegatedAdmins + ConfigurationBackups + SessionAnnotations + AdminIdentityBindings)
         Assert.All(result.Manifest.Tables, t =>
             Assert.True(t.Status == TableBackupStatus.Ok || t.Status == TableBackupStatus.Empty));
     }

src/Backend/AutopilotMonitor.Functions.Tests/CveIndexEntityMergeTests.cs

@@ -68,6 +68,32 @@ public class CveIndexEntityMergeTests
         Assert.Equal("critical", e.GetString("OverallRisk"));
     }
 
+    [Fact]
+    public void Merge_EpssMaxes_PriorityMaxes_AndUnscoredWritesNoEpssColumn()
+    {
+        var scoredLow = Vuln("CVE-1", 5.0, "MEDIUM"); scoredLow["epssScore"] = 0.02; scoredLow["priority"] = "track";
+        var scoredHigh = Vuln("CVE-1", 4.0, "MEDIUM"); scoredHigh["epssScore"] = 0.35; scoredHigh["priority"] = "attend";
+        var unscored = Vuln("CVE-1", 3.0, "LOW"); unscored["priority"] = "track";
+
+        var e = Assert.Single(TableStorageService.BuildCveIndexEntities(Tenant, Session, new List<Dictionary<string, object>>
+        {
+            Finding("App A", "medium", unscored),
+            Finding("App B", "medium", scoredLow),
+            Finding("App C", "medium", scoredHigh),
+        }));
+
+        Assert.Equal(0.35, e.GetDouble("EpssScore"));
+        Assert.Equal("attend", e.GetString("Priority"));
+
+        // A CVE nobody scored must not carry a fake 0.0 — the aggregate treats absent as "unknown".
+        var none = Assert.Single(TableStorageService.BuildCveIndexEntities(Tenant, Session, new List<Dictionary<string, object>>
+        {
+            Finding("App A", "low", Vuln("CVE-2", 3.0, "LOW")),
+        }));
+        Assert.False(none.ContainsKey("EpssScore"));
+        Assert.Equal("", none.GetString("Priority"));
+    }
+
     [Fact]
     public void DistinctCves_StayDistinct_AndInvalidEntriesAreSkipped()
     {

src/Backend/AutopilotMonitor.Functions.Tests/DelegatedAdminEditionGateTests.cs

@@ -23,6 +23,10 @@ public class DelegatedAdminEditionGateTests
     private const string CommunityHomeTenant = "22222222-2222-2222-2222-222222222222";
     private const string ManagedTenantA = "33333333-3333-3333-3333-333333333333";
     private const string ManagedTenantB = "44444444-4444-4444-4444-444444444444";
+    private const string Oid = "aaaaaaaa-1111-1111-1111-aaaaaaaaaaaa";
+
+    /// <summary>Caller identity homed in <paramref name="homeTenantId"/>; null/blank ⇒ incomplete identity (null).</summary>
+    private static AdminIdentity? Id(string? homeTenantId) => AdminIdentity.Create(Upn, homeTenantId, Oid);
 
     private static DelegatedAdminEntry Row(string tenantId) => new()
     {
@@ -43,6 +47,8 @@ public class DelegatedAdminEditionGateTests
             .ReturnsAsync(new List<TenantGroupAssignment>());
         return new DelegatedAdminService(
             repo.Object,
+            // Binding stubbed to "bound": these tests pin the EDITION gate, not the identity check.
+            new StubAdminIdentityBindingService(bound: true),
             new StubTenantEntitlementService(
                 tenantId => tenantId == EnterpriseHomeTenant ? TenantEdition.Pro : TenantEdition.Community),
             new MemoryCache(new MemoryCacheOptions()),
@@ -55,7 +61,7 @@ public class DelegatedAdminEditionGateTests
         // Managed targets resolve Community in the stub — they must NOT be dropped.
         var svc = Build(Row(ManagedTenantA), Row(ManagedTenantB));
 
-        var scope = await svc.GetScopeAsync(Upn, EnterpriseHomeTenant);
+        var scope = await svc.GetScopeAsync(Id(EnterpriseHomeTenant));
 
         Assert.True(scope.Covers(ManagedTenantA));
         Assert.True(scope.Covers(ManagedTenantB));
@@ -66,7 +72,7 @@ public class DelegatedAdminEditionGateTests
     {
         var svc = Build(Row(ManagedTenantA), Row(ManagedTenantB));
 
-        var scope = await svc.GetScopeAsync(Upn, CommunityHomeTenant);
+        var scope = await svc.GetScopeAsync(Id(CommunityHomeTenant));
 
         Assert.True(scope.IsEmpty);
     }
@@ -76,8 +82,8 @@ public class DelegatedAdminEditionGateTests
     {
         var svc = Build(Row(ManagedTenantA));
 
-        Assert.True((await svc.GetScopeAsync(Upn, null)).IsEmpty);
-        Assert.True((await svc.GetScopeAsync(Upn, "")).IsEmpty);
+        Assert.True((await svc.GetScopeAsync(Id(null))).IsEmpty);
+        Assert.True((await svc.GetScopeAsync(Id(""))).IsEmpty);
     }
 
     [Fact]
@@ -89,9 +95,9 @@ public class DelegatedAdminEditionGateTests
         // practice but the cache must stay pure either way).
         var svc = Build(Row(ManagedTenantA));
 
-        Assert.True((await svc.GetScopeAsync(Upn, CommunityHomeTenant)).IsEmpty);
-        Assert.True((await svc.GetScopeAsync(Upn, EnterpriseHomeTenant)).Covers(ManagedTenantA));
-        Assert.True((await svc.GetScopeAsync(Upn, CommunityHomeTenant)).IsEmpty);
+        Assert.True((await svc.GetScopeAsync(Id(CommunityHomeTenant))).IsEmpty);
+        Assert.True((await svc.GetScopeAsync(Id(EnterpriseHomeTenant))).Covers(ManagedTenantA));
+        Assert.True((await svc.GetScopeAsync(Id(CommunityHomeTenant))).IsEmpty);
     }
 
     [Fact]
@@ -117,14 +123,16 @@ public class DelegatedAdminEditionGateTests
 
         var svc = new DelegatedAdminService(
             repo.Object,
+            // Binding stubbed to "bound": these tests pin the EDITION gate, not the identity check.
+            new StubAdminIdentityBindingService(bound: true),
             new StubTenantEntitlementService(
                 tenantId => tenantId == EnterpriseHomeTenant ? TenantEdition.Pro : TenantEdition.Community),
             new MemoryCache(new MemoryCacheOptions()),
             NullLogger<DelegatedAdminService>.Instance);
 
-        Assert.True((await svc.GetScopeAsync(Upn, CommunityHomeTenant)).IsEmpty);
+        Assert.True((await svc.GetScopeAsync(Id(CommunityHomeTenant))).IsEmpty);
 
-        var enterpriseScope = await svc.GetScopeAsync(Upn, EnterpriseHomeTenant);
+        var enterpriseScope = await svc.GetScopeAsync(Id(EnterpriseHomeTenant));
         Assert.True(enterpriseScope.Covers(ManagedTenantA));
         Assert.True(enterpriseScope.Covers(ManagedTenantB));
     }

src/Backend/AutopilotMonitor.Functions.Tests/DelegatedAdminServiceTests.cs

@@ -1,3 +1,4 @@
+using AutopilotMonitor.Functions.Security;
 using AutopilotMonitor.Functions.Services;
 using AutopilotMonitor.Shared;
 using AutopilotMonitor.Shared.DataAccess;
@@ -16,6 +17,8 @@ namespace AutopilotMonitor.Functions.Tests;
 public class DelegatedAdminServiceTests
 {
     private const string Upn = "msp-admin@partner.example";
+    private const string HomeTenant = "99999999-9999-9999-9999-999999999999";
+    private const string Oid = "aaaaaaaa-1111-1111-1111-aaaaaaaaaaaa";
     private const string TenantA = "11111111-1111-1111-1111-111111111111";
     private const string TenantB = "22222222-2222-2222-2222-222222222222";
 
@@ -34,14 +37,20 @@ public class DelegatedAdminServiceTests
         var cache = new MemoryCache(new MemoryCacheOptions());
         // Entitlements stubbed to Enterprise for every tenant — these tests pin ROLE resolution;
         // the edition filter has its own dedicated tests (DelegatedAdminEditionGateTests).
+        // Binding stubbed to "bound" — these tests pin ROW resolution; the identity check has its own
+        // tests (AdminIdentityBindingServiceTests / AdminIdentityBindingAuthorizationTests).
         var svc = new DelegatedAdminService(
             repo.Object,
+            new StubAdminIdentityBindingService(bound: true),
             new StubTenantEntitlementService(AutopilotMonitor.Functions.Security.TenantEdition.Pro),
             cache,
             NullLogger<DelegatedAdminService>.Instance);
         return (svc, repo);
     }
 
+    /// <summary>The caller identity for a UPN: homed in <see cref="HomeTenant"/> with <see cref="Oid"/>.</summary>
+    private static AdminIdentity Id(string upn) => new(upn.ToLowerInvariant(), HomeTenant, Oid);
+
     private static TenantGroupAssignment Assignment(
         string groupId,
         string role = Constants.DelegatedRoles.DelegatedReader,
@@ -78,13 +87,17 @@ public class DelegatedAdminServiceTests
         repo.Setup(r => r.GetDelegatedTenantsAsync(It.IsAny<string>())).ReturnsAsync(rows.ToList());
 
     [Theory]
-    [InlineData(null)]
-    [InlineData("")]
-    [InlineData("   ")]
-    public async Task GetScope_BlankUpn_ReturnsEmpty(string? upn)
+    [InlineData(null, HomeTenant, Oid)]
+    [InlineData("", HomeTenant, Oid)]
+    [InlineData("   ", HomeTenant, Oid)]
+    [InlineData(Upn, null, Oid)]
+    [InlineData(Upn, HomeTenant, null)]
+    public async Task GetScope_IncompleteIdentity_ReturnsEmpty_WithoutTouchingStorage(string? upn, string? tid, string? oid)
     {
+        // upn + tid + oid are all required: a token missing any of them (app-only, or a foreign IdP shape)
+        // resolves no delegated scope and does not even read the assignment rows.
         var (svc, repo) = Build();
-        var scope = await svc.GetScopeAsync(upn);
+        var scope = await svc.GetScopeAsync(AdminIdentity.Create(upn, tid, oid));
         Assert.True(scope.IsEmpty);
         repo.Verify(r => r.GetDelegatedTenantsAsync(It.IsAny<string>()), Times.Never);
     }
@@ -93,7 +106,7 @@ public class DelegatedAdminServiceTests
     public async Task GetScope_NoRows_ReturnsEmpty()
     {
         var (svc, _) = Build();
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
         Assert.True(scope.IsEmpty);
         Assert.False(scope.Covers(TenantA));
     }
@@ -104,7 +117,7 @@ public class DelegatedAdminServiceTests
         var (svc, repo) = Build();
         Returns(repo, Row(TenantA, Constants.DelegatedRoles.DelegatedReader));
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(scope.Covers(TenantA));
         Assert.Equal(Constants.DelegatedRoles.DelegatedReader, scope.RoleFor(TenantA));
@@ -118,7 +131,7 @@ public class DelegatedAdminServiceTests
         var (svc, repo) = Build();
         Returns(repo, Row(TenantA, Constants.DelegatedRoles.DelegatedAdmin));
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(scope.CanWrite(TenantA));
     }
@@ -131,7 +144,7 @@ public class DelegatedAdminServiceTests
         var (svc, repo) = Build();
         Returns(repo, Row(TenantA, status: status));
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.False(scope.Covers(TenantA));
         Assert.True(scope.IsEmpty);
@@ -143,7 +156,7 @@ public class DelegatedAdminServiceTests
         var (svc, repo) = Build();
         Returns(repo, Row(TenantA, enabled: false));
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.False(scope.Covers(TenantA));
     }
@@ -154,7 +167,7 @@ public class DelegatedAdminServiceTests
         var (svc, repo) = Build();
         Returns(repo, Row(TenantA, role: ""));
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.Equal(Constants.DelegatedRoles.DelegatedReader, scope.RoleFor(TenantA));
     }
@@ -165,7 +178,7 @@ public class DelegatedAdminServiceTests
         var (svc, repo) = Build();
         Returns(repo, Row(TenantA, role: "SuperRoot"));
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.False(scope.Covers(TenantA));
         Assert.True(scope.IsEmpty);
@@ -179,7 +192,7 @@ public class DelegatedAdminServiceTests
             Row(TenantA, Constants.DelegatedRoles.DelegatedReader),
             Row(TenantB, Constants.DelegatedRoles.DelegatedAdmin));
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.Equal(2, scope.TenantIds.Count);
         Assert.False(scope.CanWrite(TenantA));
@@ -192,7 +205,7 @@ public class DelegatedAdminServiceTests
         var (svc, repo) = Build();
         Returns(repo, Row(TenantA.ToLowerInvariant()));
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(scope.Covers(TenantA.ToUpperInvariant()));
     }
@@ -203,8 +216,8 @@ public class DelegatedAdminServiceTests
         var (svc, repo) = Build();
         Returns(repo, Row(TenantA));
 
-        await svc.GetScopeAsync(Upn);
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
+        await svc.GetScopeAsync(Id(Upn));
 
         repo.Verify(r => r.GetDelegatedTenantsAsync(It.IsAny<string>()), Times.Once);
     }
@@ -219,10 +232,11 @@ public class DelegatedAdminServiceTests
                 It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
             .ReturnsAsync(true);
 
-        await svc.GetScopeAsync(Upn); // primes cache
+        await svc.GetScopeAsync(Id(Upn)); // primes cache
         await svc.UpsertAsync(Upn, TenantB, Constants.DelegatedRoles.DelegatedReader,
-            Constants.DelegatedStatus.Active, Constants.DelegatedSource.OperatorGranted, "ga@vendor.example");
-        await svc.GetScopeAsync(Upn); // must re-query after invalidation
+            Constants.DelegatedStatus.Active, Constants.DelegatedSource.OperatorGranted, "ga@vendor.example",
+            HomeTenant, null);
+        await svc.GetScopeAsync(Id(Upn)); // must re-query after invalidation
 
         repo.Verify(r => r.GetDelegatedTenantsAsync(It.IsAny<string>()), Times.Exactly(2));
     }
@@ -235,9 +249,9 @@ public class DelegatedAdminServiceTests
         repo.Setup(r => r.SetDelegatedAdminStatusAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
             .ReturnsAsync(true);
 
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
         await svc.SetStatusAsync(Upn, TenantA, Constants.DelegatedStatus.Revoked);
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
 
         repo.Verify(r => r.GetDelegatedTenantsAsync(It.IsAny<string>()), Times.Exactly(2));
     }
@@ -251,7 +265,7 @@ public class DelegatedAdminServiceTests
         ReturnsGroups(repo, Assignment(GroupId1, Constants.DelegatedRoles.DelegatedReader));
         GroupTenants(repo, GroupId1, TenantA, TenantB);
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.Equal(2, scope.TenantIds.Count);
         Assert.True(scope.Covers(TenantA));
@@ -267,7 +281,7 @@ public class DelegatedAdminServiceTests
         ReturnsGroups(repo, Assignment(GroupId1));
         GroupTenants(repo, GroupId1, TenantB, TenantC);
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.Equal(3, scope.TenantIds.Count);
         Assert.True(scope.Covers(TenantA));
@@ -282,7 +296,7 @@ public class DelegatedAdminServiceTests
         ReturnsGroups(repo, Assignment(GroupId1, enabled: false));
         GroupTenants(repo, GroupId1, TenantA);
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(scope.IsEmpty);
         Assert.False(scope.Covers(TenantA));
@@ -295,7 +309,7 @@ public class DelegatedAdminServiceTests
         ReturnsGroups(repo, Assignment(GroupId1, role: "SuperRoot"));
         GroupTenants(repo, GroupId1, TenantA);
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(scope.IsEmpty);
     }
@@ -307,7 +321,7 @@ public class DelegatedAdminServiceTests
         ReturnsGroups(repo, Assignment(GroupId1));
         GroupTenants(repo, GroupId1); // no tenants
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(scope.IsEmpty);
     }
@@ -320,7 +334,7 @@ public class DelegatedAdminServiceTests
         GroupTenants(repo, GroupId1, TenantA);
         GroupTenants(repo, GroupId2, TenantA, TenantB);
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.Equal(2, scope.TenantIds.Count);
         Assert.True(scope.Covers(TenantA));
@@ -335,7 +349,7 @@ public class DelegatedAdminServiceTests
         ReturnsGroups(repo, Assignment(GroupId1, Constants.DelegatedRoles.DelegatedAdmin));
         GroupTenants(repo, GroupId1, TenantA);
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(scope.CanWrite(TenantA)); // stronger DelegatedAdmin wins across sources
     }
@@ -348,7 +362,7 @@ public class DelegatedAdminServiceTests
         ReturnsGroups(repo, Assignment(GroupId1, Constants.DelegatedRoles.DelegatedReader));
         GroupTenants(repo, GroupId1, TenantA);
 
-        var scope = await svc.GetScopeAsync(Upn);
+        var scope = await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(scope.CanWrite(TenantA)); // direct DelegatedAdmin not downgraded by group reader
     }
@@ -360,8 +374,8 @@ public class DelegatedAdminServiceTests
         ReturnsGroups(repo, Assignment(GroupId1));
         GroupTenants(repo, GroupId1, TenantA);
 
-        await svc.GetScopeAsync(Upn);
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
+        await svc.GetScopeAsync(Id(Upn));
 
         repo.Verify(r => r.GetGroupAssignmentsForUpnAsync(It.IsAny<string>()), Times.Once);
         repo.Verify(r => r.GetGroupTenantsAsync(GroupId1), Times.Once);
@@ -380,9 +394,9 @@ public class DelegatedAdminServiceTests
                 It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<bool>(), It.IsAny<string>()))
             .ReturnsAsync(true);
 
-        await svc.GetScopeAsync(Upn); // primes cache
-        await svc.AssignGroupAsync(Upn, GroupId2, Constants.DelegatedRoles.DelegatedReader, true, "ga@vendor.example");
-        await svc.GetScopeAsync(Upn); // must re-resolve after invalidation
+        await svc.GetScopeAsync(Id(Upn)); // primes cache
+        await svc.AssignGroupAsync(Upn, GroupId2, Constants.DelegatedRoles.DelegatedReader, true, "ga@vendor.example", HomeTenant, null);
+        await svc.GetScopeAsync(Id(Upn)); // must re-resolve after invalidation
 
         repo.Verify(r => r.GetGroupAssignmentsForUpnAsync(It.IsAny<string>()), Times.Exactly(2));
     }
@@ -397,7 +411,7 @@ public class DelegatedAdminServiceTests
             .ReturnsAsync(true);
 
         var assigned = await svc.AssignGroupAsync(
-            Upn, GroupId1, Constants.DelegatedRoles.DelegatedReader, true, "ga@vendor.example");
+            Upn, GroupId1, Constants.DelegatedRoles.DelegatedReader, true, "ga@vendor.example", HomeTenant, null);
 
         Assert.False(assigned);
         repo.Verify(r => r.AssignGroupAsync(
@@ -412,9 +426,9 @@ public class DelegatedAdminServiceTests
         GroupTenants(repo, GroupId1, TenantA);
         repo.Setup(r => r.UnassignGroupAsync(It.IsAny<string>(), It.IsAny<string>())).ReturnsAsync(true);
 
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
         var unassigned = await svc.UnassignGroupAsync(Upn, GroupId1);
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
 
         Assert.True(unassigned);
         // Verify re-resolution via the tenant expansion (the unassign now also reads assignments itself,
@@ -459,11 +473,11 @@ public class DelegatedAdminServiceTests
             new() { Upn = upnB, GroupId = GroupId1, Role = Constants.DelegatedRoles.DelegatedReader, IsEnabled = true },
         });
 
-        await svc.GetScopeAsync(Upn);   // primes A
-        await svc.GetScopeAsync(upnB);  // primes B
+        await svc.GetScopeAsync(Id(Upn));   // primes A
+        await svc.GetScopeAsync(Id(upnB));  // primes B
         var removed = await svc.RemoveTenantFromGroupAsync(GroupId1, TenantA);
-        await svc.GetScopeAsync(Upn);   // re-resolves A
-        await svc.GetScopeAsync(upnB);  // re-resolves B
+        await svc.GetScopeAsync(Id(Upn));   // re-resolves A
+        await svc.GetScopeAsync(Id(upnB));  // re-resolves B
 
         Assert.True(removed);
         repo.Verify(r => r.GetGroupAssignmentsForUpnAsync(Upn), Times.Exactly(2));
@@ -536,9 +550,9 @@ public class DelegatedAdminServiceTests
             new() { Upn = Upn, GroupId = GroupId1, Role = Constants.DelegatedRoles.DelegatedReader, IsEnabled = true },
         });
 
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
         await svc.DeleteGroupAsync(GroupId1);
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
 
         repo.Verify(r => r.GetGroupAssignmentsForUpnAsync(Upn), Times.Exactly(2));
     }
@@ -555,7 +569,7 @@ public class DelegatedAdminServiceTests
             .ReturnsAsync(true);
 
         var assigned = await svc.AssignGroupAsync(
-            Upn, "TPL-LOWER", Constants.DelegatedRoles.DelegatedReader, true, "ga@vendor.example");
+            Upn, "TPL-LOWER", Constants.DelegatedRoles.DelegatedReader, true, "ga@vendor.example", HomeTenant, null);
 
         Assert.True(assigned);
         // Repo was looked up + written with the normalized (lowercase) id.
@@ -572,9 +586,9 @@ public class DelegatedAdminServiceTests
         GroupTenants(repo, GroupId1, TenantA);
         repo.Setup(r => r.RenameTenantGroupAsync(It.IsAny<string>(), It.IsAny<string>())).ReturnsAsync(true);
 
-        await svc.GetScopeAsync(Upn);
+        await svc.GetScopeAsync(Id(Upn));
         await svc.RenameGroupAsync(GroupId1, "Renamed");
-        await svc.GetScopeAsync(Upn); // name-only change → scope stays cached
+        await svc.GetScopeAsync(Id(Upn)); // name-only change → scope stays cached
 
         repo.Verify(r => r.GetGroupAssignmentsForUpnAsync(It.IsAny<string>()), Times.Once);
     }

src/Backend/AutopilotMonitor.Functions.Tests/DiagnosticsUploadConfigChangeTests.cs

@@ -0,0 +1,73 @@
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.Models;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// The Collect Logs capability flip that feeds the DiagnosticsUploadEnabled/Disabled ops
+/// events: only a change of "would an on-demand upload work" counts, never a plain edit.
+/// </summary>
+public class DiagnosticsUploadConfigChangeTests
+{
+    private static TenantConfiguration Cfg(string? mode, string? destination = null, string? sas = null) => new()
+    {
+        TenantId = "t1",
+        DiagnosticsUploadMode = mode!,
+        DiagnosticsUploadDestination = destination!,
+        DiagnosticsBlobSasUrl = sas!,
+    };
+
+    [Theory]
+    [InlineData(null, null, null, false)]
+    [InlineData("Off", "Hosted", null, false)]
+    [InlineData("OnFailure", null, null, false)]
+    [InlineData("OnFailure", "Hosted", null, true)]
+    [InlineData("Always", "CustomerSas", "https://x.blob.core.windows.net/c?sig=1", true)]
+    [InlineData("Always", null, "https://x.blob.core.windows.net/c?sig=1", true)]
+    public void IsConfigured_mirrors_the_feature_flag_semantics(string? mode, string? dest, string? sas, bool expected)
+    {
+        Assert.Equal(expected, DiagnosticsUploadConfigChange.IsConfigured(Cfg(mode, dest, sas)));
+        Assert.False(DiagnosticsUploadConfigChange.IsConfigured(null));
+    }
+
+    [Fact]
+    public void Detect_quick_config_flip_reports_enabled_with_destination_and_mode()
+    {
+        // The Collect Logs quick-config dialog: Off/unset -> Hosted + OnFailure.
+        var change = DiagnosticsUploadConfigChange.Detect(Cfg("Off"), Cfg("OnFailure", "Hosted"));
+
+        Assert.NotNull(change);
+        Assert.True(change!.Enabled);
+        Assert.Equal("Hosted", change.Destination);
+        Assert.Equal("OnFailure", change.Mode);
+    }
+
+    [Fact]
+    public void Detect_missing_before_row_counts_as_not_configured()
+    {
+        var change = DiagnosticsUploadConfigChange.Detect(null, Cfg("Always", "Hosted"));
+        Assert.True(change?.Enabled);
+    }
+
+    [Fact]
+    public void Detect_reports_disabled_when_mode_goes_off()
+    {
+        var change = DiagnosticsUploadConfigChange.Detect(Cfg("Always", "Hosted"), Cfg("Off", "Hosted"));
+
+        Assert.NotNull(change);
+        Assert.False(change!.Enabled);
+        Assert.Equal("Off", change.Mode);
+    }
+
+    [Fact]
+    public void Detect_ignores_edits_that_keep_the_capability_state()
+    {
+        // Mode change while staying on: no flip.
+        Assert.Null(DiagnosticsUploadConfigChange.Detect(Cfg("OnFailure", "Hosted"), Cfg("Always", "Hosted")));
+        // Destination not yet usable in both states: no flip.
+        Assert.Null(DiagnosticsUploadConfigChange.Detect(Cfg("Off"), Cfg("OnFailure")));
+        // Unchanged.
+        Assert.Null(DiagnosticsUploadConfigChange.Detect(Cfg("Off"), Cfg("Off")));
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/EmailServiceTests.cs

@@ -75,11 +75,14 @@ public sealed class EmailServiceTests
     {
         var (sut, handler, logger) = Build(apiKey: "");
 
-        await sut.SendPreviewApprovedEmailAsync("it@contoso.invalid", "contoso.invalid");
+        var sent = await sut.SendPreviewApprovedEmailAsync("it@contoso.invalid", "contoso.invalid");
 
+        Assert.False(sent);
         Assert.Equal(0, handler.CallCount);
+        // Warning, not Debug: an unconfigured provider is operator misconfiguration, and worker
+        // logs below Warning never reach Application Insights — Debug made it invisible.
         Assert.Contains(logger.Entries,
-            e => e.Level == LogLevel.Debug && e.Message.Contains("Email:ApiKey not configured"));
+            e => e.Level == LogLevel.Warning && e.Message.Contains("Email:ApiKey not configured"));
     }
 
     // ----- wire format -----

src/Backend/AutopilotMonitor.Functions.Tests/EnrollmentTimeoutClassifierTests.cs

@@ -394,14 +394,91 @@ public class EnrollmentTimeoutClassifierTests
     }
 
     [Fact]
-    public void Classify_agent_timeout_failed_session_classifies_honestly()
+    public void Classify_agent_timeout_terminalizes_immediately_instead_of_parking()
     {
-        // WG Part-2 shape (session 1506ce9f): DeviceSetup 4/4, no user phase, watchdog fired at
-        // 6h — honest verdict is AwaitingUser (within grace), never Failed.
+        // The watchdog firing proves the agent is gone for good — an AwaitingUser park from this
+        // state is a countdown, not a wait: all 5 observed maxlife:r5_awaiting episodes expired
+        // unhealed (calibration read 2026-08-27). Still never Failed, and late straggler
+        // telemetry can heal the Incomplete (TryLateTelemetryReconcileAsync).
         var timeout = Evt("enrollment_failed",
             data: new Dictionary<string, object> { ["failureType"] = "agent_timeout" });
-        var (status, _) = Classify(new[] { Esp(DeviceSetup44), timeout }, hoursSinceStart: 6);
-        Assert.Equal(SessionStatus.AwaitingUser, status);
+        var (status, reason) = Classify(new[] { Esp(DeviceSetup44), timeout }, hoursSinceStart: 6);
+        Assert.Equal(SessionStatus.Incomplete, status);
+        Assert.Contains("max-lifetime watchdog", reason);
+
+        // The V2 shutdown shape carries the same fact.
+        var shutdown = Evt("agent_shutting_down",
+            data: new Dictionary<string, object> { ["reason"] = "max_lifetime" });
+        var (viaShutdown, _) = Classify(new[] { Esp(DeviceSetup44), shutdown }, hoursSinceStart: 6);
+        Assert.Equal(SessionStatus.Incomplete, viaShutdown);
+
+        // WhiteGlove Part 2 (rule 1b) is deliberately untouched: a sealed/powered-off device
+        // between technician and end user stays AwaitingUser — that park DOES heal
+        // (the observed maxlife:r1b_awaiting episode resolved to Succeeded).
+        var rollup = EnrollmentTimeoutClassifier.ExtractRollup(new[] { Esp(DeviceSetup44), timeout });
+        var (wgStatus, _, wgRule) = EnrollmentTimeoutClassifier.ClassifyTimedOutSession(
+            rollup, Start, Start.AddHours(6), 72, isPreProvisioned: true, resumedAt: Start.AddHours(1));
+        Assert.Equal(SessionStatus.AwaitingUser, wgStatus);
+        Assert.Equal(ClassifierRules.R1bWhiteGloveAwaiting, wgRule);
+    }
+
+    // -------- Rule 5a: completed (assumed) — calibration read 2026-08-27 --------
+
+    [Fact]
+    public void ExtractRollup_detects_app_failures_and_maxlife_timeout()
+    {
+        Assert.True(EnrollmentTimeoutClassifier.ExtractRollup(new[] { Evt("app_install_failed") }).HasAppInstallFailure);
+        var timeout = Evt("enrollment_failed", data: new Dictionary<string, object> { ["failureType"] = "agent_timeout" });
+        Assert.True(EnrollmentTimeoutClassifier.ExtractRollup(new[] { timeout }).HasAgentMaxLifetimeTimeout);
+        var shutdown = Evt("agent_shutting_down", data: new Dictionary<string, object> { ["reason"] = "max_lifetime" });
+        Assert.True(EnrollmentTimeoutClassifier.ExtractRollup(new[] { shutdown }).HasAgentMaxLifetimeTimeout);
+        // Other shutdown reasons say nothing about max lifetime.
+        var ctrlC = Evt("agent_shutting_down", data: new Dictionary<string, object> { ["reason"] = "ctrl_c" });
+        Assert.False(EnrollmentTimeoutClassifier.ExtractRollup(new[] { ctrlC }).HasAgentMaxLifetimeTimeout);
+        // A real failure event does not raise the app flag.
+        Assert.False(EnrollmentTimeoutClassifier.ExtractRollup(new[] { Evt("enrollment_failed") }).HasAppInstallFailure);
+    }
+
+    [Fact]
+    public void Classify_desktop_without_hello_past_grace_is_assumed_complete()
+    {
+        // The healthy half of the r5 population (drill-down 2026-08-27): desktop reached, apps
+        // clean, agent died before the Hello terminal. Past the full grace "user phase still
+        // running" is no longer a possible explanation — completed (assumed), not a red Incomplete.
+        var (status, reason, rule) = ClassifyWithRule(new[]
+        {
+            Esp(DeviceSetup44), Esp(AccountSetup15), Evt("desktop_arrived"),
+        }, hoursSinceStart: 80, grace: 72);
+        Assert.Equal(SessionStatus.Succeeded, status);
+        Assert.Equal(ClassifierRules.R5DesktopAssumed, rule);
+        Assert.Contains("treating the enrollment as completed", reason);
+        Assert.Contains("Agent last reported", reason); // silence-transparency clause
+    }
+
+    [Fact]
+    public void Classify_desktop_with_app_failure_past_grace_stays_Incomplete()
+    {
+        // "Completed" must not overclaim a session whose ESP payload provably failed
+        // (drill-down session b1edc6f8: desktop reached but .NET 3.5 install failed).
+        var (status, _) = Classify(new[]
+        {
+            Esp(DeviceSetup44), Evt("desktop_arrived"), Evt("app_install_failed"),
+        }, hoursSinceStart: 80, grace: 72);
+        Assert.Equal(SessionStatus.Incomplete, status);
+    }
+
+    [Fact]
+    public void Classify_maxlife_with_desktop_and_clean_apps_is_assumed_complete_within_grace()
+    {
+        // Agent provably gone + desktop + clean apps: no reason to park — the assumption is as
+        // good now as it would be after the 51h grace.
+        var timeout = Evt("enrollment_failed", data: new Dictionary<string, object> { ["failureType"] = "agent_timeout" });
+        var (status, _, rule) = ClassifyWithRule(new[]
+        {
+            Esp(DeviceSetup44), Evt("desktop_arrived"), timeout,
+        }, hoursSinceStart: 6);
+        Assert.Equal(SessionStatus.Succeeded, status);
+        Assert.Equal(ClassifierRules.R5DesktopAssumed, rule);
     }
 
     [Fact]

src/Backend/AutopilotMonitor.Functions.Tests/EpssAndNvdThrottleTests.cs

@@ -0,0 +1,350 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Threading;
+using System.Threading.Tasks;
+using AutopilotMonitor.Functions.Services.Vulnerability;
+using Microsoft.Extensions.Logging.Abstractions;
+using Xunit;
+using static AutopilotMonitor.Functions.Services.Vulnerability.VulnerabilityCorrelationService;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Pins the EPSS integration and the NVD throttle contract:
+/// FIRST's envelope parses with invariant-culture string numbers, a 429 opens a bounded cooldown
+/// (Retry-After honoured but capped), the NVD→cache projection carries the CVSS vector, EPSS
+/// application never erases an existing score, and the act/attend/track priority is exactly the
+/// three documented rules.
+/// </summary>
+public class EpssAndNvdThrottleTests
+{
+    // -----------------------------------------------------------------------
+    // EpssApiClient
+    // -----------------------------------------------------------------------
+
+    private const string SampleEnvelope = """
+        {"status":"OK","status-code":200,"version":"1.0","access":"public","total":2,"offset":0,"limit":100,
+         "data":[
+           {"cve":"CVE-2024-21447","epss":"0.00383","percentile":"0.73461","date":"2026-08-28"},
+           {"cve":"cve-2023-4863","epss":"0.94210","percentile":"0.99891","date":"2026-08-28"},
+           {"cve":"CVE-2020-0001","epss":"not-a-number","percentile":"0.5","date":"2026-08-28"},
+           {"cve":"","epss":"0.1","percentile":"0.5","date":"2026-08-28"}
+         ]}
+        """;
+
+    [Fact]
+    public void ParseResponse_ParsesInvariantStrings_AndDropsUnparseableRows()
+    {
+        var scores = EpssApiClient.ParseResponse(SampleEnvelope);
+
+        Assert.Equal(2, scores.Count);
+        var a = scores.Single(s => s.CveId == "CVE-2024-21447");
+        Assert.Equal(0.00383, a.Score, 6);
+        Assert.Equal(0.73461, a.Percentile, 6);
+        Assert.Equal("2026-08-28", a.Date);
+        // Ids are normalised to upper case so cache lookups are stable.
+        Assert.Contains(scores, s => s.CveId == "CVE-2023-4863");
+    }
+
+    [Fact]
+    public void ParseResponse_EmptyOrMissingData_ReturnsEmpty()
+    {
+        Assert.Empty(EpssApiClient.ParseResponse("""{"status":"OK","data":[]}"""));
+        Assert.Empty(EpssApiClient.ParseResponse("""{"status":"OK"}"""));
+    }
+
+    private sealed class StubHandler : HttpMessageHandler
+    {
+        public List<Uri> Requests { get; } = new();
+        private readonly Func<HttpRequestMessage, HttpResponseMessage> _respond;
+        public StubHandler(Func<HttpRequestMessage, HttpResponseMessage> respond) => _respond = respond;
+        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken ct)
+        {
+            Requests.Add(request.RequestUri!);
+            return Task.FromResult(_respond(request));
+        }
+    }
+
+    [Fact]
+    public async Task GetScoresAsync_BatchesByHundred_DedupesIds_AndSurvivesAFailedBatch()
+    {
+        int call = 0;
+        var handler = new StubHandler(req =>
+        {
+            call++;
+            if (call == 2)
+                return new HttpResponseMessage(HttpStatusCode.InternalServerError);
+            // Echo the first id of the batch back as scored.
+            var query = Uri.UnescapeDataString(req.RequestUri!.Query);
+            var firstId = query.Substring("?cve=".Length).Split(',')[0];
+            return new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent($$"""{"status":"OK","data":[{"cve":"{{firstId}}","epss":"0.5","percentile":"0.9","date":"2026-08-28"}]}""")
+            };
+        });
+        var client = new EpssApiClient(new HttpClient(handler), NullLogger<EpssApiClient>.Instance);
+
+        // 150 distinct ids + 10 duplicates (case-varied) ⇒ exactly two requests.
+        var ids = Enumerable.Range(1, 150).Select(i => $"CVE-2024-{10000 + i}").ToList();
+        ids.AddRange(ids.Take(10).Select(id => id.ToLowerInvariant()));
+
+        var result = await client.GetScoresAsync(ids);
+
+        Assert.Equal(2, handler.Requests.Count);
+        Assert.Single(result); // batch 1 scored one id, batch 2 failed soft
+        Assert.True(result.ContainsKey("cve-2024-10001")); // case-insensitive map
+        Assert.All(handler.Requests, u => Assert.StartsWith(EpssApiClient.EpssUrl, u.ToString()));
+    }
+
+    // -----------------------------------------------------------------------
+    // NVD throttle cooldown
+    // -----------------------------------------------------------------------
+
+    private static readonly DateTime Now = new(2026, 8, 29, 12, 0, 0, DateTimeKind.Utc);
+
+    [Fact]
+    public void ComputeCooldown_NoHeader_UsesDefault()
+    {
+        Assert.Equal(NvdApiClient.ThrottleCooldown, NvdApiClient.ComputeCooldown(null, Now));
+    }
+
+    [Fact]
+    public void ComputeCooldown_RetryAfterDelta_IsHonoured()
+    {
+        var header = new RetryConditionHeaderValue(TimeSpan.FromSeconds(45));
+        Assert.Equal(TimeSpan.FromSeconds(45), NvdApiClient.ComputeCooldown(header, Now));
+    }
+
+    [Fact]
+    public void ComputeCooldown_RetryAfterDate_IsRelativeToNow()
+    {
+        var header = new RetryConditionHeaderValue(new DateTimeOffset(Now.AddSeconds(20)));
+        Assert.Equal(TimeSpan.FromSeconds(20), NvdApiClient.ComputeCooldown(header, Now));
+    }
+
+    [Fact]
+    public void ComputeCooldown_IsCapped_SoAServerCannotParkUsForAnHour()
+    {
+        var header = new RetryConditionHeaderValue(TimeSpan.FromHours(1));
+        Assert.Equal(NvdApiClient.MaxRetryAfter, NvdApiClient.ComputeCooldown(header, Now));
+    }
+
+    [Fact]
+    public void ComputeCooldown_PastDateOrZero_FallsBackToDefault()
+    {
+        Assert.Equal(NvdApiClient.ThrottleCooldown,
+            NvdApiClient.ComputeCooldown(new RetryConditionHeaderValue(new DateTimeOffset(Now.AddSeconds(-5))), Now));
+        Assert.Equal(NvdApiClient.ThrottleCooldown,
+            NvdApiClient.ComputeCooldown(new RetryConditionHeaderValue(TimeSpan.Zero), Now));
+    }
+
+    [Fact]
+    public void NvdFetchResult_FailureShapes_CarryEmptyDataButNeverSucceeded()
+    {
+        var throttled = NvdFetchResult<NvdCveResponse>.ThrottledResult();
+        Assert.False(throttled.Succeeded);
+        Assert.True(throttled.Throttled);
+        Assert.NotNull(throttled.Data);
+        Assert.Empty(throttled.Data.Vulnerabilities);
+
+        var failed = NvdFetchResult<NvdCveResponse>.Failed();
+        Assert.False(failed.Succeeded);
+        Assert.False(failed.Throttled);
+
+        var ok = NvdFetchResult<NvdCveResponse>.Ok(new NvdCveResponse { TotalResults = 1 });
+        Assert.True(ok.Succeeded);
+        Assert.Equal(1, ok.Data.TotalResults);
+    }
+
+    // -----------------------------------------------------------------------
+    // NVD → CachedCve projection
+    // -----------------------------------------------------------------------
+
+    [Fact]
+    public void ProjectNvdResponse_CarriesVector_PrefersV31_AndKeepsOnlyVulnerableRanges()
+    {
+        var response = new NvdCveResponse
+        {
+            Vulnerabilities =
+            {
+                new NvdVulnerabilityItem
+                {
+                    Cve = new NvdCve
+                    {
+                        Id = "CVE-2024-1",
+                        Published = "2026-01-01T00:00:00.000",
+                        Descriptions = { new NvdDescription { Lang = "en", Value = "desc" } },
+                        Metrics = new NvdMetrics
+                        {
+                            CvssMetricV30 = { new NvdCvssMetricV31 { CvssData = new NvdCvssData { BaseScore = 5, BaseSeverity = "MEDIUM", VectorString = "CVSS:3.0/AV:L" } } },
+                            CvssMetricV31 = { new NvdCvssMetricV31 { CvssData = new NvdCvssData { BaseScore = 9.8, BaseSeverity = "CRITICAL", VectorString = "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H" } } },
+                        },
+                        Configurations =
+                        {
+                            new NvdConfiguration
+                            {
+                                Nodes =
+                                {
+                                    new NvdNode
+                                    {
+                                        CpeMatch =
+                                        {
+                                            new NvdCpeMatch { Vulnerable = true, Criteria = "cpe:2.3:a:v:p:*:*:*:*:*:*:*:*", VersionEndExcluding = "2.0" },
+                                            new NvdCpeMatch { Vulnerable = false, Criteria = "cpe:2.3:o:microsoft:windows:*:*:*:*:*:*:*:*" },
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                },
+                new NvdVulnerabilityItem
+                {
+                    Cve = new NvdCve { Id = "CVE-2024-2", Descriptions = { new NvdDescription { Lang = "en", Value = "no metrics" } } }
+                },
+            }
+        };
+
+        var cves = VulnerabilityCorrelationService.ProjectNvdResponse(response);
+
+        Assert.Equal(2, cves.Count);
+        var first = cves[0];
+        Assert.Equal(9.8, first.CvssScore);
+        Assert.Equal("CRITICAL", first.CvssSeverity);
+        Assert.Equal("CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", first.CvssVector);
+        Assert.Single(first.AffectedVersions);
+        Assert.Equal("2.0", first.AffectedVersions[0].VersionEndExcluding);
+        Assert.Null(first.EpssScore); // never defaulted before enrichment
+
+        var second = cves[1];
+        Assert.Equal(0, second.CvssScore);
+        Assert.Equal("UNKNOWN", second.CvssSeverity);
+        Assert.Null(second.CvssVector);
+    }
+
+    [Fact]
+    public void ProjectNvdResponse_Null_ReturnsEmpty()
+    {
+        Assert.Empty(VulnerabilityCorrelationService.ProjectNvdResponse(null));
+    }
+
+    // -----------------------------------------------------------------------
+    // EPSS application onto cached CVEs
+    // -----------------------------------------------------------------------
+
+    [Fact]
+    public void ApplyEpssScores_SetsNewScores_KeepsUnscoredUntouched_AndReportsOnlyChanges()
+    {
+        var cves = new List<CachedCve>
+        {
+            new() { CveId = "CVE-1", EpssScore = 0.2, EpssPercentile = 0.8, EpssDate = "2026-08-27" },
+            new() { CveId = "CVE-2" },
+            new() { CveId = "CVE-3", EpssScore = 0.5, EpssPercentile = 0.9, EpssDate = "2026-08-28" },
+        };
+        var scores = new Dictionary<string, EpssScore>(StringComparer.OrdinalIgnoreCase)
+        {
+            ["cve-1"] = new EpssScore { CveId = "CVE-1", Score = 0.25, Percentile = 0.85, Date = "2026-08-28" }, // changed
+            ["CVE-3"] = new EpssScore { CveId = "CVE-3", Score = 0.5, Percentile = 0.9, Date = "2026-08-28" },   // unchanged
+            // CVE-2 absent: FIRST did not score it (or its batch failed) ⇒ stays null
+        };
+
+        var changed = VulnerabilityCorrelationService.ApplyEpssScores(cves, scores);
+
+        Assert.Equal(1, changed);
+        Assert.Equal(0.25, cves[0].EpssScore);
+        Assert.Equal("2026-08-28", cves[0].EpssDate);
+        Assert.Null(cves[1].EpssScore);
+        Assert.Equal(0.5, cves[2].EpssScore);
+    }
+
+    [Fact]
+    public void ApplyEpssScores_NeverErasesYesterdaysScore_WhenTodayHasNone()
+    {
+        var cves = new List<CachedCve> { new() { CveId = "CVE-1", EpssScore = 0.3, EpssPercentile = 0.7, EpssDate = "2026-08-27" } };
+        var changed = VulnerabilityCorrelationService.ApplyEpssScores(cves, new Dictionary<string, EpssScore>());
+        Assert.Equal(0, changed);
+        Assert.Equal(0.3, cves[0].EpssScore);
+    }
+
+    [Fact]
+    public void BuildCveCacheRow_PassesCachedAtThrough_SoEpssRewritesDoNotLookLikeNvdFetches()
+    {
+        var cachedAt = new DateTime(2026, 8, 20, 3, 0, 0, DateTimeKind.Utc);
+        var row = VulnerabilityCorrelationService.BuildCveCacheRow("cpe:2.3:a:v:p", new List<CachedCve> { new() { CveId = "CVE-1" } }, cachedAt);
+
+        Assert.Equal(cachedAt.ToString("o"), row["CachedAt"]);
+        Assert.Equal("cpe:2.3:a:v:p", row["CpeUri"]);
+        Assert.Equal(1, row["TotalCves"]);
+        Assert.True(row.ContainsKey("CveDataJson"));
+    }
+
+    [Fact]
+    public void CachedCve_RoundTrips_WithoutWritingNulls_SoLegacyRowsStayReadable()
+    {
+        var json = System.Text.Json.JsonSerializer.Serialize(new List<CachedCve> { new() { CveId = "CVE-1", CvssScore = 7 } }, JsonOptions);
+        Assert.DoesNotContain("EpssScore", json);
+        Assert.DoesNotContain("CvssVector", json);
+
+        // A row written before this change (no EPSS/vector properties at all) still deserialises.
+        var legacy = """[{"CveId":"CVE-9","CvssScore":4.3,"CvssSeverity":"MEDIUM","Description":"","PublishedDate":"","AffectedVersions":[]}]""";
+        var cves = System.Text.Json.JsonSerializer.Deserialize<List<CachedCve>>(legacy, JsonOptions)!;
+        Assert.Null(cves[0].EpssScore);
+        Assert.Null(cves[0].CvssVector);
+    }
+
+    // -----------------------------------------------------------------------
+    // Priority
+    // -----------------------------------------------------------------------
+
+    [Theory]
+    [InlineData(true, null, 0.0, CvePriority.Act)]
+    [InlineData(true, 0.001, 2.0, CvePriority.Act)]
+    [InlineData(false, 0.1, 2.0, CvePriority.Attend)]
+    [InlineData(false, 0.0999, 2.0, CvePriority.Track)]
+    [InlineData(false, null, 9.0, CvePriority.Attend)]
+    [InlineData(false, 0.0, 9.8, CvePriority.Attend)]
+    [InlineData(false, null, 8.9, CvePriority.Track)]
+    [InlineData(false, 0.05, 7.5, CvePriority.Track)]
+    public void Compute_FollowsTheThreeRules(bool kev, double? epss, double cvss, string expected)
+    {
+        Assert.Equal(expected, CvePriority.Compute(kev, epss, cvss));
+    }
+
+    [Fact]
+    public void Max_PicksHigherBand_AndTreatsUnknownAsLowest()
+    {
+        Assert.Equal(CvePriority.Act, CvePriority.Max(CvePriority.Track, CvePriority.Act));
+        Assert.Equal(CvePriority.Attend, CvePriority.Max(CvePriority.Attend, null));
+        Assert.Equal(CvePriority.Track, CvePriority.Max(null, ""));
+    }
+
+    [Fact]
+    public void StampFindingPriority_RollsUpHighestBand_AndMaxEpss()
+    {
+        var finding = new Dictionary<string, object> { ["maxEpssScore"] = 0.9 /* stale value, must be recomputed */ };
+        var vulns = new List<object>
+        {
+            new Dictionary<string, object> { ["priority"] = CvePriority.Track, ["epssScore"] = 0.02 },
+            new Dictionary<string, object> { ["priority"] = CvePriority.Attend, ["epssScore"] = 0.4 },
+            new Dictionary<string, object> { ["priority"] = CvePriority.Track },
+        };
+
+        VulnerabilityCorrelationService.StampFindingPriority(finding, vulns);
+
+        Assert.Equal(CvePriority.Attend, finding["priority"]);
+        Assert.Equal(0.4, finding["maxEpssScore"]);
+    }
+
+    [Fact]
+    public void StampFindingPriority_NoScoredCves_OmitsMaxEpss()
+    {
+        var finding = new Dictionary<string, object>();
+        VulnerabilityCorrelationService.StampFindingPriority(finding, new List<object> { new Dictionary<string, object> { ["priority"] = CvePriority.Track } });
+        Assert.Equal(CvePriority.Track, finding["priority"]);
+        Assert.False(finding.ContainsKey("maxEpssScore"));
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/GetImeVersionHistoryRedactionTests.cs

@@ -124,7 +124,7 @@ public class GetImeVersionHistoryRedactionTests
             new[]
             {
                 "firstSeenAt", "firstSeenSessionId", "firstSeenTenantId", "lastSeenAt",
-                "msiArchiveBlobPath", "msiArchiveStatus", "msiBytes", "msiSha256", "msiSourceUrl",
+                "msiArchiveBlobPath", "msiArchiveStatus", "msiArchiveUpdatedAt", "msiBytes", "msiSha256", "msiSourceUrl",
                 "sessionCount", "version",
             },
             keys);
@@ -211,6 +211,7 @@ public class GetImeVersionHistoryRedactionTests
             LastSeenAt = Last,
             SessionCount = 3109,
             MsiArchiveStatus = "Archived",
+            MsiArchiveUpdatedAt = Last,
             MsiArchiveBlobPath = $"{version}/IntuneWindowsAgent.msi",
             MsiSha256 = "4d6b85fd3c49cf227ab4711308bca1f3c701cad9bff1799da4c6b6616066bb5e",
             MsiBytes = 13_107_200,

src/Backend/AutopilotMonitor.Functions.Tests/ImeMsiArchiveQueueWorkerTests.cs

@@ -36,14 +36,14 @@ public class ImeMsiArchiveQueueWorkerTests
         var harness = new Harness();
         harness.Archiver.Result = new ImeMsiArchiveResult(
             true, ImeMsiArchiver.Statuses.Archived, Retryable: false,
-            $"{Version}/IntuneWindowsAgent.msi", "abc123", 42L, ImeMsiArchiver.CanonicalMsiUrl);
+            $"{Version}/IntuneWindowsAgent.msi", "abc123", 42L, ImeMsiArchiver.FallbackMsiUrls[1]);
         harness.EnqueueMessage(JsonConvert.SerializeObject(Envelope()));
 
         await harness.RunUntilAsync(() => harness.MainQueueDeleted());
 
         harness.Repo.Verify(r => r.UpdateImeVersionArchiveInfoAsync(
             Version, ImeMsiArchiver.Statuses.Archived,
-            $"{Version}/IntuneWindowsAgent.msi", "abc123", 42L, ImeMsiArchiver.CanonicalMsiUrl),
+            $"{Version}/IntuneWindowsAgent.msi", "abc123", 42L, ImeMsiArchiver.FallbackMsiUrls[1]),
             Times.Once);
         harness.MainQueue.Verify(q => q.DeleteMessageAsync(
             It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()),
@@ -56,7 +56,7 @@ public class ImeMsiArchiveQueueWorkerTests
         var harness = new Harness();
         harness.Archiver.Result = new ImeMsiArchiveResult(
             false, ImeMsiArchiver.Statuses.FailedDownload, Retryable: true,
-            null, null, null, ImeMsiArchiver.CanonicalMsiUrl);
+            null, null, null, ImeMsiArchiver.FallbackMsiUrls[1]);
         harness.EnqueueMessage(JsonConvert.SerializeObject(Envelope()));
 
         await harness.RunUntilAsync(() => harness.Archiver.Calls > 0);
@@ -64,7 +64,7 @@ public class ImeMsiArchiveQueueWorkerTests
         // Row always tells the truth — the failure status IS merged...
         harness.Repo.Verify(r => r.UpdateImeVersionArchiveInfoAsync(
             Version, ImeMsiArchiver.Statuses.FailedDownload,
-            null, null, null, ImeMsiArchiver.CanonicalMsiUrl),
+            null, null, null, ImeMsiArchiver.FallbackMsiUrls[1]),
             Times.AtLeastOnce);
         // ...but the message stays for the visibility-timeout retry → poison ladder.
         harness.MainQueue.Verify(q => q.DeleteMessageAsync(
@@ -78,14 +78,14 @@ public class ImeMsiArchiveQueueWorkerTests
         var harness = new Harness();
         harness.Archiver.Result = new ImeMsiArchiveResult(
             false, ImeMsiArchiver.Statuses.FailedTooLarge, Retryable: false,
-            null, null, 999L, ImeMsiArchiver.CanonicalMsiUrl);
+            null, null, 999L, ImeMsiArchiver.FallbackMsiUrls[1]);
         harness.EnqueueMessage(JsonConvert.SerializeObject(Envelope()));
 
         await harness.RunUntilAsync(() => harness.MainQueueDeleted());
 
         harness.Repo.Verify(r => r.UpdateImeVersionArchiveInfoAsync(
             Version, ImeMsiArchiver.Statuses.FailedTooLarge,
-            null, null, 999L, ImeMsiArchiver.CanonicalMsiUrl),
+            null, null, 999L, ImeMsiArchiver.FallbackMsiUrls[1]),
             Times.Once);
         harness.MainQueue.Verify(q => q.DeleteMessageAsync(
             It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()),
@@ -131,7 +131,7 @@ public class ImeMsiArchiveQueueWorkerTests
     private static ImeMsiArchiveEnvelope Envelope() => new()
     {
         Version = Version,
-        MsiDownloadUrl = ImeMsiArchiver.CanonicalMsiUrl,
+        MsiDownloadUrl = ImeMsiArchiver.FallbackMsiUrls[1],
         MsiMatchedBy = "productVersion",
         TenantId = "11111111-1111-1111-1111-111111111111",
         SessionId = "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",

src/Backend/AutopilotMonitor.Functions.Tests/ImeMsiArchiverTests.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Net.Http;
 using System.Security.Cryptography;
 using System.Threading;
@@ -15,15 +16,21 @@ namespace AutopilotMonitor.Functions.Tests;
 /// <summary>
 /// The IME-installer archiver downloads a newly sighted IME build into the permanent
 /// ime-archive container. Its contract: NEVER throw (worker decides retry from the result),
-/// treat the agent-supplied URL as untrusted (allowlist, else canonical fallback), enforce
-/// the size cap both at Content-Length preflight and mid-stream, and stay idempotent under
-/// queue re-delivery (409 on the write-once upload == archived). Tests pin every status
-/// branch via a recording subclass — no Azurite, no HTTP.
+/// treat the agent-supplied URL as untrusted (allowlist, else distribution hosts only),
+/// enforce the size cap both at Content-Length preflight and mid-stream, stay idempotent
+/// under queue re-delivery (409 on the write-once upload == archived) — and, since
+/// 2026-08-29, NEVER file bytes under a version they are not: every candidate download's
+/// ProductVersion is checked against the observed version and the hosts are walked in
+/// order until one matches. Tests pin every status branch via a recording subclass — no
+/// Azurite, no HTTP, no disk.
 /// </summary>
 public class ImeMsiArchiverTests
 {
     private const string Version = "1.104.102.0";
     private const string EventUrl = "https://imeswdb-afd-secondary.manage.microsoft.com/IntuneWindowsAgent.msi";
+    private const string PrimaryUrl = "https://imeswda-afd-primary.manage.microsoft.com/IntuneWindowsAgent.msi";
+    private const string SecondaryUrl = "https://imeswdb-afd-secondary.manage.microsoft.com/IntuneWindowsAgent.msi";
+    private const string HotfixUrl = "https://imeswda-afd-hotfix.manage.microsoft.com/IntuneWindowsAgent.msi";
 
     // =========================================================================
     // URL allowlist (static — the SSRF boundary)
@@ -49,6 +56,83 @@ public class ImeMsiArchiverTests
         Assert.Equal(expected, ImeMsiArchiver.IsAllowedMsiUrl(url));
     }
 
+    // =========================================================================
+    // Candidate order — event URL first, then every distribution host, no duplicates
+    // =========================================================================
+
+    [Fact]
+    public void BuildCandidateUrls_EventUrlFirst_ThenHosts_Deduplicated()
+    {
+        var custom = "https://swda01-mscdn.manage.microsoft.com/IntuneWindowsAgent.msi";
+
+        Assert.Equal(new[] { custom, PrimaryUrl, SecondaryUrl, HotfixUrl }, ImeMsiArchiver.BuildCandidateUrls(custom));
+        // Event URL equal to a host (any casing) is not tried twice.
+        Assert.Equal(new[] { SecondaryUrl.ToUpperInvariant(), PrimaryUrl, HotfixUrl },
+            ImeMsiArchiver.BuildCandidateUrls(SecondaryUrl.ToUpperInvariant()));
+        Assert.Equal(new[] { PrimaryUrl, SecondaryUrl, HotfixUrl }, ImeMsiArchiver.BuildCandidateUrls(null));
+        Assert.Equal(new[] { PrimaryUrl, SecondaryUrl, HotfixUrl },
+            ImeMsiArchiver.BuildCandidateUrls("https://evil.example.com/IntuneWindowsAgent.msi"));
+    }
+
+    [Theory]
+    [InlineData("1.105.103.0", "1.105.103.0", true)]
+    [InlineData("1.105.103.0", "1.105.103", true)]   // trailing zero dropped by the MSI
+    [InlineData("1.105.103", "1.105.103.0", true)]
+    [InlineData(" 1.105.103.0 ", "1.105.103.0", true)]
+    [InlineData("1.105.103.0", "1.104.102.0", false)]
+    [InlineData("1.105.103.0", null, false)]         // unreadable package never matches
+    [InlineData("1.105.103.0", "", false)]
+    [InlineData("1.105.103.0", "latest", false)]
+    public void VersionsMatch_cases(string observed, string? productVersion, bool expected)
+    {
+        Assert.Equal(expected, ImeMsiArchiver.VersionsMatch(observed, productVersion));
+    }
+
+    // =========================================================================
+    // Re-queue rule for later sightings of a known version
+    // =========================================================================
+
+    public static IEnumerable<object?[]> RequeueCases()
+    {
+        var now = new DateTime(2026, 8, 29, 12, 0, 0, DateTimeKind.Utc);
+        var fresh = now.AddHours(-1);
+        var stale = now.AddHours(-25);
+        static object?[] Case(bool isNew, string? status, DateTime? updatedAt, string? url, string? matchedBy, bool expected) =>
+            new object?[] { isNew, status, updatedAt, url, matchedBy, expected };
+
+        yield return Case(false, "Failed:VersionMismatch", stale, HotfixUrl, "productVersion", true);
+        yield return Case(false, "Failed:VersionMismatch", null, HotfixUrl, "productVersion", true);   // never stamped
+        yield return Case(false, null, null, HotfixUrl, "productVersion", true);                        // predates archiver / manual backfill
+        yield return Case(false, "Queued", stale, HotfixUrl, "productVersion", true);                   // lost message, backoff elapsed
+        yield return Case(false, "Failed:Download", stale, HotfixUrl, "productVersion", true);          // poisoned after retries
+        yield return Case(false, "Failed:TooLarge", stale, HotfixUrl, "productVersion", true);          // cap may have changed
+        yield return Case(false, "Failed:VersionMismatch", fresh, HotfixUrl, "productVersion", false);  // backoff
+        yield return Case(false, "Queued", fresh, HotfixUrl, "productVersion", false);                  // already in flight
+        yield return Case(false, "Archived", stale, HotfixUrl, "productVersion", false);
+        yield return Case(false, "Failed:BadVersion", stale, HotfixUrl, "productVersion", false);       // permanent
+        yield return Case(false, "Failed:VersionMismatch", stale, HotfixUrl, "fileName", false);        // URL not authoritative
+        yield return Case(false, "Failed:VersionMismatch", stale, HotfixUrl, null, false);
+        yield return Case(false, "Failed:VersionMismatch", stale, null, "productVersion", false);       // no URL
+        yield return Case(false, "Failed:VersionMismatch", stale, "https://evil.example.com/IntuneWindowsAgent.msi", "productVersion", false);
+        yield return Case(true, null, null, HotfixUrl, "productVersion", false);                        // first sighting has its own path
+    }
+
+    [Theory]
+    [MemberData(nameof(RequeueCases))]
+    public void ShouldRequeueOnSighting_cases(bool isNew, string? status, DateTime? updatedAt, string? url, string? matchedBy, bool expected)
+    {
+        var now = new DateTime(2026, 8, 29, 12, 0, 0, DateTimeKind.Utc);
+        var sighting = new ImeVersionSighting { IsNew = isNew, MsiArchiveStatus = status, MsiArchiveUpdatedAt = updatedAt };
+
+        Assert.Equal(expected, ImeMsiArchiver.ShouldRequeueOnSighting(sighting, url, matchedBy, now));
+    }
+
+    [Fact]
+    public void ShouldRequeueOnSighting_NullSighting_False()
+    {
+        Assert.False(ImeMsiArchiver.ShouldRequeueOnSighting(null, HotfixUrl, "productVersion", DateTime.UtcNow));
+    }
+
     // =========================================================================
     // Version guard (blob path is built from untrusted input)
     // =========================================================================
@@ -72,33 +156,131 @@ public class ImeMsiArchiverTests
     }
 
     // =========================================================================
-    // URL selection
+    // URL selection + version verification
     // =========================================================================
 
     [Fact]
-    public async Task ArchiveAsync_AllowedEventUrl_IsUsed()
+    public async Task ArchiveAsync_AllowedEventUrl_ServingObservedVersion_IsUsedFirst()
     {
         var archiver = new RecordingArchiver();
 
         var result = await archiver.ArchiveAsync(Envelope(url: EventUrl));
 
         Assert.True(result.Success);
-        Assert.Equal(EventUrl, archiver.DownloadLastUrl);
+        Assert.Equal(1, archiver.DownloadCalls);
+        Assert.Equal(EventUrl, archiver.DownloadUrls.Single());
         Assert.Equal(EventUrl, result.SourceUrl);
     }
 
     [Theory]
     [InlineData("https://evil.example.com/IntuneWindowsAgent.msi")] // allowlist reject
     [InlineData(null)]                                              // pre-enrichment agent
-    public async Task ArchiveAsync_MissingOrRejectedEventUrl_FallsBackToCanonical(string? url)
+    public async Task ArchiveAsync_MissingOrRejectedEventUrl_StartsWithPrimaryHost(string? url)
     {
         var archiver = new RecordingArchiver();
 
         var result = await archiver.ArchiveAsync(Envelope(url: url));
 
         Assert.True(result.Success);
-        Assert.Equal(ImeMsiArchiver.CanonicalMsiUrl, archiver.DownloadLastUrl);
-        Assert.Equal(ImeMsiArchiver.CanonicalMsiUrl, result.SourceUrl);
+        Assert.Equal(PrimaryUrl, archiver.DownloadUrls.Single());
+        Assert.Equal(PrimaryUrl, result.SourceUrl);
+    }
+
+    /// <summary>
+    /// THE 2026-08-29 incident: the event carried no URL, the secondary host still served
+    /// the previous build and it got archived under the new version. Now the wrong build is
+    /// detected and the walk continues to the host that actually serves the version.
+    /// </summary>
+    [Fact]
+    public async Task ArchiveAsync_HostsServeOtherBuilds_WalksUntilProductVersionMatches()
+    {
+        var archiver = new RecordingArchiver
+        {
+            ProductVersionByUrl =
+            {
+                [PrimaryUrl] = "1.105.101.0",
+                [SecondaryUrl] = "1.104.102.0",
+                [HotfixUrl] = "1.105.103.0",
+            },
+        };
+
+        var result = await archiver.ArchiveAsync(Envelope(version: "1.105.103.0", url: null));
+
+        Assert.True(result.Success);
+        Assert.Equal(ImeMsiArchiver.Statuses.Archived, result.Status);
+        Assert.Equal(new[] { PrimaryUrl, SecondaryUrl, HotfixUrl }, archiver.DownloadUrls);
+        Assert.Equal(HotfixUrl, result.SourceUrl);
+        Assert.Equal("1.105.103.0/IntuneWindowsAgent.msi", result.BlobPath);
+        Assert.Equal(1, archiver.UploadCalls);
+        // Provenance records the verified version and the full walk.
+        Assert.Contains("\"productVersion\": \"1.105.103.0\"", archiver.ProvenanceLastJson);
+        Assert.Contains("version-mismatch", archiver.ProvenanceLastJson);
+        Assert.Contains("1.105.101.0", archiver.ProvenanceLastJson);
+        Assert.Contains("\"urlFromEvent\": false", archiver.ProvenanceLastJson);
+    }
+
+    [Fact]
+    public async Task ArchiveAsync_EventUrlServesWrongBuild_FallsThroughToHosts()
+    {
+        var custom = "https://swda01-mscdn.manage.microsoft.com/IntuneWindowsAgent.msi";
+        var archiver = new RecordingArchiver
+        {
+            ProductVersionByUrl = { [custom] = "1.103.101.0", [PrimaryUrl] = Version },
+        };
+
+        var result = await archiver.ArchiveAsync(Envelope(url: custom));
+
+        Assert.True(result.Success);
+        Assert.Equal(new[] { custom, PrimaryUrl }, archiver.DownloadUrls);
+        Assert.Equal(PrimaryUrl, result.SourceUrl);
+    }
+
+    [Fact]
+    public async Task ArchiveAsync_NoHostServesVersion_VersionMismatch_NotRetryable_NoUpload()
+    {
+        var archiver = new RecordingArchiver { DefaultProductVersion = "1.104.102.0" };
+
+        var result = await archiver.ArchiveAsync(Envelope(version: "1.105.103.0", url: EventUrl));
+
+        Assert.False(result.Success);
+        Assert.Equal(ImeMsiArchiver.Statuses.FailedVersionMismatch, result.Status);
+        Assert.False(result.Retryable);
+        Assert.Null(result.SourceUrl);
+        Assert.Equal(3, archiver.DownloadCalls); // event URL == secondary → deduped
+        Assert.Equal(0, archiver.UploadCalls);
+        Assert.Equal(0, archiver.ProvenanceCalls);
+    }
+
+    [Fact]
+    public async Task ArchiveAsync_UnreadablePackage_TreatedAsMismatch()
+    {
+        var archiver = new RecordingArchiver { DefaultProductVersion = null };
+
+        var result = await archiver.ArchiveAsync(Envelope());
+
+        Assert.False(result.Success);
+        Assert.Equal(ImeMsiArchiver.Statuses.FailedVersionMismatch, result.Status);
+        Assert.Equal(0, archiver.UploadCalls);
+    }
+
+    [Fact]
+    public async Task ArchiveAsync_UploadReceivesTheVerifiedBytes()
+    {
+        var right = new byte[4096];
+        new Random(1).NextBytes(right);
+        var wrong = new byte[4096];
+        new Random(2).NextBytes(wrong);
+        var archiver = new RecordingArchiver
+        {
+            PayloadByUrl = { [PrimaryUrl] = wrong, [SecondaryUrl] = right },
+            ProductVersionByUrl = { [PrimaryUrl] = "0.0.0.1", [SecondaryUrl] = Version },
+        };
+
+        var result = await archiver.ArchiveAsync(Envelope(url: null));
+
+        Assert.True(result.Success);
+        Assert.Equal(Convert.ToHexString(SHA256.HashData(right)).ToLowerInvariant(), result.Sha256);
+        Assert.Equal(right, archiver.UploadedBytes);
     }
 
     // =========================================================================
@@ -127,14 +309,15 @@ public class ImeMsiArchiverTests
         Assert.Equal($"{Version}/provenance.json", archiver.ProvenanceLastPath);
         Assert.Contains(expectedSha, archiver.ProvenanceLastJson);
         Assert.Contains(Version, archiver.ProvenanceLastJson);
+        Assert.Contains("\"urlFromEvent\": true", archiver.ProvenanceLastJson);
     }
 
     // =========================================================================
-    // Size cap — preflight and mid-stream
+    // Size cap — preflight and mid-stream (applies per candidate)
     // =========================================================================
 
     [Fact]
-    public async Task ArchiveAsync_ContentLengthAboveCap_Rejected_NoUpload()
+    public async Task ArchiveAsync_ContentLengthAboveCap_OnEveryHost_Rejected_NoUpload()
     {
         var archiver = new RecordingArchiver
         {
@@ -170,6 +353,22 @@ public class ImeMsiArchiverTests
         Assert.Equal(0, archiver.ProvenanceCalls);
     }
 
+    [Fact]
+    public async Task ArchiveAsync_OversizedFirstHost_SmallerMatchingHostStillArchives()
+    {
+        var archiver = new RecordingArchiver
+        {
+            MaxDownloadSizeMB = 1,
+            PayloadByUrl = { [PrimaryUrl] = new byte[2 * 1024 * 1024], [SecondaryUrl] = new byte[2048] },
+        };
+
+        var result = await archiver.ArchiveAsync(Envelope(url: null));
+
+        Assert.True(result.Success);
+        Assert.Equal(SecondaryUrl, result.SourceUrl);
+        Assert.Contains("too-large", archiver.ProvenanceLastJson);
+    }
+
     [Fact]
     public async Task ArchiveAsync_CapZero_MeansUnlimited()
     {
@@ -301,11 +500,11 @@ public class ImeMsiArchiverTests
     }
 
     // =========================================================================
-    // Transient failures — retryable, never thrown
+    // Transient failures — retryable, never thrown; one bad host does not end the walk
     // =========================================================================
 
     [Fact]
-    public async Task ArchiveAsync_DownloadFails_RetryableDownloadStatus()
+    public async Task ArchiveAsync_AllHostsFailToDownload_RetryableDownloadStatus()
     {
         var archiver = new RecordingArchiver
         {
@@ -314,6 +513,40 @@ public class ImeMsiArchiverTests
 
         var result = await archiver.ArchiveAsync(Envelope());
 
+        Assert.False(result.Success);
+        Assert.Equal(ImeMsiArchiver.Statuses.FailedDownload, result.Status);
+        Assert.True(result.Retryable);
+        Assert.Equal(3, archiver.DownloadCalls);
+    }
+
+    [Fact]
+    public async Task ArchiveAsync_FirstHostDown_NextHostArchives()
+    {
+        var archiver = new RecordingArchiver
+        {
+            DownloadExceptionByUrl = { [PrimaryUrl] = new HttpRequestException("503") },
+        };
+
+        var result = await archiver.ArchiveAsync(Envelope(url: null));
+
+        Assert.True(result.Success);
+        Assert.Equal(SecondaryUrl, result.SourceUrl);
+        Assert.Contains("download-failed", archiver.ProvenanceLastJson);
+    }
+
+    [Fact]
+    public async Task ArchiveAsync_TransientFailurePlusMismatch_ReportsTransient_SoTheQueueRetries()
+    {
+        // One host down, the rest serving another build: the down host might have had the
+        // version — worth the queue's retry ladder rather than a permanent mismatch.
+        var archiver = new RecordingArchiver
+        {
+            DefaultProductVersion = "0.0.0.1",
+            DownloadExceptionByUrl = { [HotfixUrl] = new HttpRequestException("503") },
+        };
+
+        var result = await archiver.ArchiveAsync(Envelope(url: null));
+
         Assert.False(result.Success);
         Assert.Equal(ImeMsiArchiver.Statuses.FailedDownload, result.Status);
         Assert.True(result.Retryable);
@@ -380,47 +613,68 @@ public class ImeMsiArchiverTests
     private sealed class RecordingArchiver : ImeMsiArchiver
     {
         public byte[] Payload { get; set; } = new byte[2048];
+        public Dictionary<string, byte[]> PayloadByUrl { get; } = new(StringComparer.OrdinalIgnoreCase);
+        /// <summary>ProductVersion the fake reader reports for a URL's bytes; falls back to <see cref="DefaultProductVersion"/>.</summary>
+        public Dictionary<string, string?> ProductVersionByUrl { get; } = new(StringComparer.OrdinalIgnoreCase);
+        /// <summary>Default = the envelope version under test, i.e. every host serves the right build unless told otherwise.</summary>
+        public string? DefaultProductVersion { get; set; } = Version;
         public bool ReportContentLength { get; set; } = true;
         public int MaxDownloadSizeMB { get; set; } = 250;
         public Exception? DownloadException { get; set; }
+        public Dictionary<string, Exception> DownloadExceptionByUrl { get; } = new(StringComparer.OrdinalIgnoreCase);
         public Exception? UploadException { get; set; }
         public Exception? ProvenanceException { get; set; }
         public bool ProvenanceExists { get; set; } = true;
         public byte[]? ArchivedPayload { get; set; }
         public Exception? ArchivedOpenException { get; set; }
 
-        public int DownloadCalls { get; private set; }
-        public string? DownloadLastUrl { get; private set; }
+        public int DownloadCalls => DownloadUrls.Count;
+        public List<string> DownloadUrls { get; } = new();
         public int UploadCalls { get; private set; }
         public string? UploadLastPath { get; private set; }
         public long UploadedByteCount { get; private set; }
+        public byte[] UploadedBytes { get; private set; } = Array.Empty<byte>();
         public int ProvenanceCalls { get; private set; }
         public string? ProvenanceLastPath { get; private set; }
         public string ProvenanceLastJson { get; private set; } = string.Empty;
 
+        private string? _currentUrl;
+
         protected override Task<AdminConfiguration> GetAdminConfigurationAsync()
             => Task.FromResult(new AdminConfiguration { MaxImeMsiDownloadSizeMB = MaxDownloadSizeMB });
 
         protected override Task<(Stream Content, long ContentLength)> OpenDownloadAsync(
             string url, CancellationToken cancellationToken)
         {
-            DownloadCalls++;
-            DownloadLastUrl = url;
+            DownloadUrls.Add(url);
+            _currentUrl = url;
+            if (DownloadExceptionByUrl.TryGetValue(url, out var perUrl)) throw perUrl;
             if (DownloadException is not null) throw DownloadException;
+            var payload = PayloadByUrl.TryGetValue(url, out var p) ? p : Payload;
             return Task.FromResult(
-                ((Stream)new MemoryStream(Payload), ReportContentLength ? Payload.LongLength : -1L));
+                ((Stream)new MemoryStream(payload), ReportContentLength ? payload.LongLength : -1L));
+        }
+
+        protected override Stream CreateSpool() => new MemoryStream();
+
+        protected override string? ReadProductVersion(Stream msi)
+        {
+            // The bytes are opaque test payloads — resolve "what version is this" by origin.
+            Assert.True(msi.CanSeek);
+            Assert.Equal(0, msi.Position);
+            return _currentUrl is not null && ProductVersionByUrl.TryGetValue(_currentUrl, out var v)
+                ? v
+                : DefaultProductVersion;
         }
 
         protected override async Task UploadMsiAsync(string blobPath, Stream content, CancellationToken cancellationToken)
         {
             UploadCalls++;
             UploadLastPath = blobPath;
-            // Drain the stream like the real blob upload would — this is what drives the
-            // hashing/cap wrapper (and mid-stream aborts surface here as exceptions).
-            var buffer = new byte[64 * 1024];
-            int read;
-            while ((read = await content.ReadAsync(buffer, cancellationToken)) > 0)
-                UploadedByteCount += read;
+            using var ms = new MemoryStream();
+            await content.CopyToAsync(ms, cancellationToken);
+            UploadedBytes = ms.ToArray();
+            UploadedByteCount += UploadedBytes.Length;
             if (UploadException is not null) throw UploadException;
         }
 

src/Backend/AutopilotMonitor.Functions.Tests/McpUserServiceDelegatedTests.cs

@@ -1,3 +1,4 @@
+using AutopilotMonitor.Functions.Security;
 using AutopilotMonitor.Functions.Services;
 using AutopilotMonitor.Shared;
 using AutopilotMonitor.Shared.DataAccess;
@@ -20,6 +21,7 @@ public class McpUserServiceDelegatedTests
     private const string DelegatedUpn = "msp@contoso.com";
     private const string TenantA = "11111111-1111-1111-1111-111111111111";
     private const string TenantB = "22222222-2222-2222-2222-222222222222";
+    private const string Oid = "aaaaaaaa-1111-1111-1111-aaaaaaaaaaaa";
 
     private readonly Mock<GlobalAdminService> _globalAdmin;
     private readonly Mock<DelegatedAdminService> _delegatedAdmin;
@@ -32,18 +34,20 @@ public class McpUserServiceDelegatedTests
         var cache = new MemoryCache(new MemoryCacheOptions());
         _adminRepo = new Mock<IAdminRepository>();
 
+        var bindings = new StubAdminIdentityBindingService(bound: true);
         _globalAdmin = new Mock<GlobalAdminService>(
-            _adminRepo.Object, cache, NullLogger<GlobalAdminService>.Instance) { CallBase = false };
+            _adminRepo.Object, bindings, cache, NullLogger<GlobalAdminService>.Instance) { CallBase = false };
         _delegatedAdmin = new Mock<DelegatedAdminService>(
             _adminRepo.Object,
+            bindings,
             new StubTenantEntitlementService(AutopilotMonitor.Functions.Security.TenantEdition.Pro),
             cache, NullLogger<DelegatedAdminService>.Instance) { CallBase = false };
         _adminConfig = new Mock<AdminConfigurationService>(
             Mock.Of<IConfigRepository>(), NullLogger<AdminConfigurationService>.Instance, cache) { CallBase = false };
 
         // Defaults: no platform role, no delegated scope, WhitelistOnly, no McpUsers row (NotPresent).
-        _globalAdmin.Setup(x => x.GetGlobalRoleAsync(It.IsAny<string>())).ReturnsAsync((string?)null);
-        _delegatedAdmin.Setup(x => x.GetScopeAsync(It.IsAny<string>(), It.IsAny<string?>())).ReturnsAsync(DelegatedScope.Empty);
+        _globalAdmin.Setup(x => x.GetGlobalRoleAsync(It.IsAny<AdminIdentity?>())).ReturnsAsync((string?)null);
+        _delegatedAdmin.Setup(x => x.GetScopeAsync(It.IsAny<AdminIdentity?>())).ReturnsAsync(DelegatedScope.Empty);
         _adminRepo.Setup(x => x.GetMcpUserAsync(It.IsAny<string>())).ReturnsAsync((McpUserEntry?)null);
         SetPolicy(McpAccessPolicy.WhitelistOnly);
 
@@ -61,7 +65,7 @@ public class McpUserServiceDelegatedTests
         var map = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
         foreach (var (tenant, role) in assignments)
             map[tenant.ToLowerInvariant()] = role;
-        _delegatedAdmin.Setup(x => x.GetScopeAsync(It.IsAny<string>(), It.IsAny<string?>()))
+        _delegatedAdmin.Setup(x => x.GetScopeAsync(It.IsAny<AdminIdentity?>()))
             .ReturnsAsync(new DelegatedScope(map));
     }
 
@@ -71,7 +75,7 @@ public class McpUserServiceDelegatedTests
         SetDelegated((TenantA, Constants.DelegatedRoles.DelegatedReader),
                      (TenantB, Constants.DelegatedRoles.DelegatedReader));
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.True(result.IsAllowed);
         Assert.False(result.IsGlobalAdmin);
@@ -93,7 +97,7 @@ public class McpUserServiceDelegatedTests
         SetDelegated((TenantA, Constants.DelegatedRoles.DelegatedReader),
                      (TenantB, Constants.DelegatedRoles.DelegatedAdmin));
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.True(result.IsAllowed);
         Assert.Equal(Constants.DelegatedRoles.DelegatedAdmin, result.DelegatedRole);
@@ -105,7 +109,7 @@ public class McpUserServiceDelegatedTests
         SetPolicy(McpAccessPolicy.Disabled);
         SetDelegated((TenantA, Constants.DelegatedRoles.DelegatedReader));
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.False(result.IsAllowed);
     }
@@ -113,11 +117,11 @@ public class McpUserServiceDelegatedTests
     [Fact]
     public async Task GlobalAdmin_WhoIsAlsoDelegated_ReportsBothPlatformAndDelegatedScope()
     {
-        _globalAdmin.Setup(x => x.GetGlobalRoleAsync(It.IsAny<string>()))
+        _globalAdmin.Setup(x => x.GetGlobalRoleAsync(It.IsAny<AdminIdentity?>()))
             .ReturnsAsync(Constants.GlobalRoles.GlobalAdmin);
         SetDelegated((TenantA, Constants.DelegatedRoles.DelegatedReader));
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.True(result.IsAllowed);
         Assert.True(result.IsGlobalAdmin);
@@ -129,7 +133,7 @@ public class McpUserServiceDelegatedTests
     [Fact]
     public async Task NoScope_NotWhitelisted_UnderWhitelistOnly_IsDenied_WithNoDelegatedInfo()
     {
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.False(result.IsAllowed);
         Assert.Null(result.DelegatedTenantIds);
@@ -142,7 +146,7 @@ public class McpUserServiceDelegatedTests
         _adminRepo.Setup(x => x.GetMcpUserAsync(It.IsAny<string>()))
             .ReturnsAsync(new McpUserEntry { Upn = DelegatedUpn, IsEnabled = true });
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.True(result.IsAllowed);
         Assert.Equal("McpUser", result.AccessGrant);
@@ -160,7 +164,7 @@ public class McpUserServiceDelegatedTests
         _adminRepo.Setup(x => x.GetMcpUserAsync(It.IsAny<string>()))
             .ReturnsAsync(new McpUserEntry { Upn = DelegatedUpn, IsEnabled = false });
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.False(result.IsAllowed);
     }
@@ -174,7 +178,7 @@ public class McpUserServiceDelegatedTests
         _adminRepo.Setup(x => x.GetMcpUserAsync(It.IsAny<string>()))
             .ReturnsAsync(new McpUserEntry { Upn = DelegatedUpn, IsEnabled = false });
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.False(result.IsAllowed);
     }
@@ -186,7 +190,7 @@ public class McpUserServiceDelegatedTests
         // still be granted — only an explicit Disabled row denies.
         SetPolicy(McpAccessPolicy.AllMembers);
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.True(result.IsAllowed);
         Assert.Equal("AllMembers", result.AccessGrant);
@@ -197,12 +201,12 @@ public class McpUserServiceDelegatedTests
     {
         // The Disabled row wins over EVERY grant path, including a platform role — the kill-switch
         // is absolute, so an operator never has to reason about which grant path a user holds.
-        _globalAdmin.Setup(x => x.GetGlobalRoleAsync(It.IsAny<string>()))
+        _globalAdmin.Setup(x => x.GetGlobalRoleAsync(It.IsAny<AdminIdentity?>()))
             .ReturnsAsync(Constants.GlobalRoles.GlobalAdmin);
         _adminRepo.Setup(x => x.GetMcpUserAsync(It.IsAny<string>()))
             .ReturnsAsync(new McpUserEntry { Upn = DelegatedUpn, IsEnabled = false });
 
-        var result = await _sut.IsAllowedAsync(DelegatedUpn);
+        var result = await _sut.IsAllowedAsync(DelegatedUpn, TenantA, Oid);
 
         Assert.False(result.IsAllowed);
     }

src/Backend/AutopilotMonitor.Functions.Tests/MsiProductVersionReaderTests.cs

@@ -0,0 +1,430 @@
+using System;
+using System.Buffers.Binary;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using AutopilotMonitor.Functions.Services.Ime;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// The MSI product-version reader is what stops the IME archiver from filing the wrong
+/// build under a version folder (2026-08-29: Microsoft's versionless CDN hosts serve
+/// different rings, so "new version == what the canonical URL serves" was false). These
+/// tests build minimal OLE compound files in memory — mini-stream and regular-sector
+/// layouts, long (>64 KB) pool strings, deleted-string holes, 3-byte string refs — and
+/// pin the failure contract (never throw, null on anything unreadable). The local sweep
+/// over real IME packages is the oracle for the string-pool id convention.
+/// </summary>
+public class MsiProductVersionReaderTests
+{
+    // =========================================================================
+    // Stream-name decoding
+    // =========================================================================
+
+    [Theory]
+    [InlineData("!_StringPool")]
+    [InlineData("!_StringData")]
+    [InlineData("!Property")]
+    [InlineData("!ActionText")]
+    [InlineData("Binary.x")]
+    public void DecodeStreamName_RoundTripsEncoder(string name)
+    {
+        Assert.Equal(name, MsiProductVersionReader.DecodeStreamName(MsiBuilder.EncodeName(name)));
+    }
+
+    [Fact]
+    public void DecodeStreamName_LeavesPlainNamesAlone()
+    {
+        Assert.Equal("SummaryInformation", MsiProductVersionReader.DecodeStreamName("SummaryInformation"));
+    }
+
+    // =========================================================================
+    // Synthetic packages
+    // =========================================================================
+
+    [Fact]
+    public void MiniStreamPackage_ReadsProductVersion()
+    {
+        var msi = MsiBuilder.Build(new Dictionary<string, string>
+        {
+            ["ProductName"] = "Microsoft Intune Management Extension",
+            ["ProductVersion"] = "1.105.103.0",
+            ["Manufacturer"] = "Microsoft Corporation",
+        });
+
+        Assert.Equal("1.105.103.0", MsiProductVersionReader.TryReadProductVersion(msi));
+    }
+
+    [Fact]
+    public void RegularSectorPackage_WithLongStringAndHoleBeforeVersion_KeepsIdsAligned()
+    {
+        // _StringData grows past the 4 KB mini-stream cutoff AND the pool contains a >64 KB
+        // string (two pool entries, one id) plus a deleted-string hole before ProductVersion —
+        // every later id must still resolve to the right text.
+        var msi = MsiBuilder.Build(
+            new Dictionary<string, string>
+            {
+                ["ProductVersion"] = "1.104.102.0",
+                ["ProductName"] = "IME",
+            },
+            extraStringsBeforeProperties: new[] { new string('x', 70_000), MsiBuilder.Hole, "filler" });
+
+        var table = MsiProductVersionReader.ReadPropertyTable(msi);
+
+        Assert.NotNull(table);
+        Assert.Equal("1.104.102.0", table!["ProductVersion"]);
+        Assert.Equal("IME", table["ProductName"]);
+    }
+
+    [Fact]
+    public void ThreeByteStringRefs_AreHonoured()
+    {
+        var msi = MsiBuilder.Build(
+            new Dictionary<string, string> { ["ProductVersion"] = "1.99.101.0" },
+            threeByteRefs: true);
+
+        Assert.Equal("1.99.101.0", MsiProductVersionReader.TryReadProductVersion(msi));
+    }
+
+    [Fact]
+    public void MissingProductVersionProperty_ReturnsNull()
+    {
+        var msi = MsiBuilder.Build(new Dictionary<string, string> { ["ProductName"] = "IME" });
+
+        Assert.Null(MsiProductVersionReader.TryReadProductVersion(msi));
+    }
+
+    [Fact]
+    public void MissingPropertyStream_ReturnsNull()
+    {
+        var msi = MsiBuilder.Build(new Dictionary<string, string> { ["ProductVersion"] = "1.0.0.0" }, omitPropertyTable: true);
+
+        Assert.Null(MsiProductVersionReader.TryReadProductVersion(msi));
+    }
+
+    [Fact]
+    public void NotACompoundFile_ReturnsNull()
+    {
+        var random = new byte[64 * 1024];
+        new Random(42).NextBytes(random);
+
+        Assert.Null(MsiProductVersionReader.TryReadProductVersion(new MemoryStream(random)));
+        Assert.Null(MsiProductVersionReader.TryReadProductVersion(new MemoryStream(Array.Empty<byte>())));
+        Assert.Null(MsiProductVersionReader.TryReadProductVersion(new MemoryStream(Encoding.ASCII.GetBytes("MZ not an msi"))));
+    }
+
+    [Fact]
+    public void TruncatedPackage_ReturnsNull_NeverThrows()
+    {
+        var full = ((MemoryStream)MsiBuilder.Build(new Dictionary<string, string> { ["ProductVersion"] = "1.0.0.0" })).ToArray();
+
+        foreach (var cut in new[] { 8, 511, 512, 600, 1024, full.Length / 2, full.Length - 1 })
+        {
+            var truncated = new MemoryStream(full.Take(cut).ToArray());
+            var ex = Record.Exception(() => MsiProductVersionReader.TryReadProductVersion(truncated));
+            Assert.Null(ex);
+        }
+    }
+
+    [Fact]
+    public void CyclicFatChain_ReturnsNull_NeverHangs()
+    {
+        var bytes = ((MemoryStream)MsiBuilder.Build(new Dictionary<string, string> { ["ProductVersion"] = "1.0.0.0" })).ToArray();
+        // FAT lives in sector 0 (offset 512). Point the directory sector's FAT entry back at itself.
+        var firstDirSector = BinaryPrimitives.ReadUInt32LittleEndian(bytes.AsSpan(0x30, 4));
+        BinaryPrimitives.WriteUInt32LittleEndian(bytes.AsSpan(512 + (int)firstDirSector * 4, 4), firstDirSector);
+
+        Assert.Null(MsiProductVersionReader.TryReadProductVersion(new MemoryStream(bytes)));
+    }
+
+    [Fact]
+    public void NonSeekableStream_ReturnsNull()
+    {
+        using var stream = new NonSeekableStream(((MemoryStream)MsiBuilder.Build(new Dictionary<string, string> { ["ProductVersion"] = "1.0.0.0" })).ToArray());
+
+        Assert.Null(MsiProductVersionReader.TryReadProductVersion(stream));
+    }
+
+    // =========================================================================
+    // Real packages (local oracle — the archived IME MSIs are not checked in)
+    // =========================================================================
+
+    /// <summary>
+    /// Sweeps every <c>ime-files/&lt;version&gt;/IntuneWindowsAgent.msi</c> in the repo checkout
+    /// (gitignored decompile scratch, populated by /ime-decompile) and asserts the reader
+    /// returns exactly the folder's version. Silently passes when the folder is absent (CI)
+    /// — the synthetic tests above carry the contract there; this one pins the string-pool
+    /// id convention against Microsoft's real packages.
+    /// </summary>
+    [Fact]
+    public void LocalImeArchive_EveryPackageReportsItsFolderVersion()
+    {
+        var root = FindRepoRoot();
+        var archive = root is null ? null : Path.Combine(root, "ime-files");
+        if (archive is null || !Directory.Exists(archive)) return;
+
+        var checkedCount = 0;
+        foreach (var dir in Directory.GetDirectories(archive))
+        {
+            var msiPath = Path.Combine(dir, "IntuneWindowsAgent.msi");
+            if (!File.Exists(msiPath)) continue;
+            var expected = Path.GetFileName(dir);
+
+            using var stream = File.OpenRead(msiPath);
+            var table = MsiProductVersionReader.ReadPropertyTable(stream);
+
+            Assert.NotNull(table);
+            Assert.Equal(expected, table!["ProductVersion"]);
+            Assert.Contains("Intune", table["ProductName"]);
+            checkedCount++;
+        }
+        Assert.True(checkedCount > 0, "ime-files exists but holds no packages");
+    }
+
+    private static string? FindRepoRoot()
+    {
+        var dir = new DirectoryInfo(AppContext.BaseDirectory);
+        while (dir is not null)
+        {
+            if (File.Exists(Path.Combine(dir.FullName, "AutopilotMonitor.sln"))) return dir.FullName;
+            dir = dir.Parent;
+        }
+        return null;
+    }
+
+    private sealed class NonSeekableStream : MemoryStream
+    {
+        public NonSeekableStream(byte[] data) : base(data) { }
+        public override bool CanSeek => false;
+    }
+
+    // =========================================================================
+    // Minimal MSI (OLE compound file v3, 512-byte sectors) builder
+    // =========================================================================
+
+    internal static class MsiBuilder
+    {
+        public const string Hole = "\0<hole>";
+        private const int SectorSize = 512;
+        private const int MiniSectorSize = 64;
+        private const int MiniCutoff = 4096;
+        private const uint EndOfChain = 0xFFFFFFFE;
+        private const uint FreeSector = 0xFFFFFFFF;
+        private const uint NoStream = 0xFFFFFFFF;
+        private const string Alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz._";
+
+        public static string EncodeName(string name)
+        {
+            var sb = new StringBuilder();
+            var i = 0;
+            if (name.StartsWith('!'))
+            {
+                sb.Append((char)0x4840);
+                i = 1;
+            }
+            for (; i < name.Length; i += 2)
+            {
+                var a = Alphabet.IndexOf(name[i]);
+                if (a < 0) { sb.Append(name[i]); i--; continue; }
+                if (i + 1 < name.Length && Alphabet.IndexOf(name[i + 1]) >= 0)
+                    sb.Append((char)(0x3800 + a + (Alphabet.IndexOf(name[i + 1]) << 6)));
+                else
+                    sb.Append((char)(0x4800 + a));
+            }
+            return sb.ToString();
+        }
+
+        public static Stream Build(
+            Dictionary<string, string> properties,
+            string[]? extraStringsBeforeProperties = null,
+            bool threeByteRefs = false,
+            bool omitPropertyTable = false)
+        {
+            // ---- string pool ----
+            var pool = new List<byte>();
+            var data = new List<byte>();
+            var ids = new Dictionary<string, int>(StringComparer.Ordinal);
+            var codepage = 1252;
+            pool.AddRange(BitConverter.GetBytes((ushort)codepage));
+            pool.AddRange(BitConverter.GetBytes((ushort)(threeByteRefs ? 0x8000 : 0)));
+            var nextId = 1;
+
+            void AddString(string s)
+            {
+                if (s == Hole)
+                {
+                    pool.AddRange(new byte[4]); // len 0, refs 0 — deleted string
+                    nextId++;
+                    return;
+                }
+                var bytes = Encoding.Latin1.GetBytes(s);
+                if (bytes.Length <= 0xFFFF)
+                {
+                    pool.AddRange(BitConverter.GetBytes((ushort)bytes.Length));
+                    pool.AddRange(BitConverter.GetBytes((ushort)1));
+                    ids[s] = nextId++;
+                }
+                else
+                {
+                    pool.AddRange(BitConverter.GetBytes((ushort)0));
+                    pool.AddRange(BitConverter.GetBytes((ushort)1));
+                    pool.AddRange(BitConverter.GetBytes((uint)bytes.Length));
+                    ids[s] = nextId;
+                    nextId += 2; // the length entry consumes a pool slot but no id
+                }
+                data.AddRange(bytes);
+            }
+
+            foreach (var s in extraStringsBeforeProperties ?? Array.Empty<string>()) AddString(s);
+            foreach (var kv in properties.OrderBy(k => k.Key, StringComparer.Ordinal))
+            {
+                if (!ids.ContainsKey(kv.Key)) AddString(kv.Key);
+                if (!ids.ContainsKey(kv.Value)) AddString(kv.Value);
+            }
+
+            // ---- Property table (column-major) ----
+            var refBytes = threeByteRefs ? 3 : 2;
+            var table = new List<byte>();
+            var ordered = properties.OrderBy(k => k.Key, StringComparer.Ordinal).ToList();
+            foreach (var kv in ordered) WriteRef(table, ids[kv.Key], refBytes);
+            foreach (var kv in ordered) WriteRef(table, ids[kv.Value], refBytes);
+
+            var streams = new List<(string Name, byte[] Bytes)>
+            {
+                (EncodeName("!_StringPool"), pool.ToArray()),
+                (EncodeName("!_StringData"), data.ToArray()),
+                ("SummaryInformation", new byte[100]),
+            };
+            if (!omitPropertyTable) streams.Add((EncodeName("!Property"), table.ToArray()));
+
+            return Assemble(streams);
+        }
+
+        private static void WriteRef(List<byte> target, int id, int refBytes)
+        {
+            target.Add((byte)(id & 0xFF));
+            target.Add((byte)((id >> 8) & 0xFF));
+            if (refBytes == 3) target.Add((byte)((id >> 16) & 0xFF));
+        }
+
+        private static Stream Assemble(List<(string Name, byte[] Bytes)> streams)
+        {
+            // Mini stream: every stream < cutoff, padded to 64-byte mini sectors, one mini-FAT chain each.
+            var miniStream = new List<byte>();
+            var miniFat = new List<uint>();
+            var miniStarts = new Dictionary<int, uint>();
+            for (var i = 0; i < streams.Count; i++)
+            {
+                if (streams[i].Bytes.Length >= MiniCutoff) continue;
+                var count = Math.Max(1, (streams[i].Bytes.Length + MiniSectorSize - 1) / MiniSectorSize);
+                miniStarts[i] = (uint)miniFat.Count;
+                for (var s = 0; s < count; s++)
+                    miniFat.Add(s == count - 1 ? EndOfChain : (uint)(miniFat.Count + 1));
+                miniStream.AddRange(streams[i].Bytes);
+                miniStream.AddRange(new byte[count * MiniSectorSize - streams[i].Bytes.Length]);
+            }
+
+            // Regular-sector payloads: directory, mini-FAT, mini stream, large streams.
+            var payloads = new List<byte[]>(); // index → bytes (each occupies ceil(len/512) sectors)
+            var dirIndex = payloads.Count; payloads.Add(Array.Empty<byte>()); // filled later
+            var miniFatIndex = payloads.Count; payloads.Add(miniFat.SelectMany(BitConverter.GetBytes).ToArray());
+            var miniStreamIndex = payloads.Count; payloads.Add(miniStream.ToArray());
+            var largeIndex = new Dictionary<int, int>();
+            for (var i = 0; i < streams.Count; i++)
+            {
+                if (streams[i].Bytes.Length < MiniCutoff) continue;
+                largeIndex[i] = payloads.Count;
+                payloads.Add(streams[i].Bytes);
+            }
+
+            // Directory entries: root + one per stream.
+            var dir = new byte[(streams.Count + 1) * 128];
+            static int SectorsFor(int len) => Math.Max(1, (len + SectorSize - 1) / SectorSize);
+            payloads[dirIndex] = dir;
+
+            // Sector map: FAT sectors first, then payloads in order.
+            var payloadSectors = payloads.Sum(p => SectorsFor(p.Length));
+            var fatSectors = 1;
+            while ((fatSectors + payloadSectors) > fatSectors * (SectorSize / 4)) fatSectors++;
+            var starts = new uint[payloads.Count];
+            var cursor = (uint)fatSectors;
+            for (var i = 0; i < payloads.Count; i++)
+            {
+                starts[i] = cursor;
+                cursor += (uint)SectorsFor(payloads[i].Length);
+            }
+            var totalSectors = (int)cursor;
+
+            // FAT
+            var fat = new uint[fatSectors * (SectorSize / 4)];
+            Array.Fill(fat, FreeSector);
+            for (var i = 0; i < fatSectors; i++) fat[i] = 0xFFFFFFFD; // FATSECT
+            for (var i = 0; i < payloads.Count; i++)
+            {
+                var n = SectorsFor(payloads[i].Length);
+                for (var s = 0; s < n; s++)
+                    fat[starts[i] + s] = s == n - 1 ? EndOfChain : starts[i] + (uint)s + 1;
+            }
+
+            // Directory content
+            WriteDirEntry(dir, 0, "Root Entry", type: 5, left: NoStream, right: NoStream, child: 1,
+                start: starts[miniStreamIndex], size: (uint)miniStream.Count);
+            for (var i = 0; i < streams.Count; i++)
+            {
+                var (start, size) = streams[i].Bytes.Length >= MiniCutoff
+                    ? (starts[largeIndex[i]], (uint)streams[i].Bytes.Length)
+                    : (miniStarts[i], (uint)streams[i].Bytes.Length);
+                WriteDirEntry(dir, i + 1, streams[i].Name, type: 2, left: NoStream,
+                    right: i + 1 < streams.Count ? (uint)(i + 2) : NoStream, child: NoStream, start, size);
+            }
+
+            // Header
+            var header = new byte[SectorSize];
+            new byte[] { 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1 }.CopyTo(header, 0);
+            BinaryPrimitives.WriteUInt16LittleEndian(header.AsSpan(0x18, 2), 0x3E); // minor
+            BinaryPrimitives.WriteUInt16LittleEndian(header.AsSpan(0x1A, 2), 3);    // major
+            BinaryPrimitives.WriteUInt16LittleEndian(header.AsSpan(0x1C, 2), 0xFFFE);
+            BinaryPrimitives.WriteUInt16LittleEndian(header.AsSpan(0x1E, 2), 9);
+            BinaryPrimitives.WriteUInt16LittleEndian(header.AsSpan(0x20, 2), 6);
+            BinaryPrimitives.WriteUInt32LittleEndian(header.AsSpan(0x2C, 4), (uint)fatSectors);
+            BinaryPrimitives.WriteUInt32LittleEndian(header.AsSpan(0x30, 4), starts[dirIndex]);
+            BinaryPrimitives.WriteUInt32LittleEndian(header.AsSpan(0x38, 4), MiniCutoff);
+            BinaryPrimitives.WriteUInt32LittleEndian(header.AsSpan(0x3C, 4), starts[miniFatIndex]);
+            BinaryPrimitives.WriteUInt32LittleEndian(header.AsSpan(0x40, 4), (uint)SectorsFor(payloads[miniFatIndex].Length));
+            BinaryPrimitives.WriteUInt32LittleEndian(header.AsSpan(0x44, 4), EndOfChain);
+            BinaryPrimitives.WriteUInt32LittleEndian(header.AsSpan(0x48, 4), 0);
+            for (var i = 0; i < 109; i++)
+                BinaryPrimitives.WriteUInt32LittleEndian(header.AsSpan(0x4C + i * 4, 4), i < fatSectors ? (uint)i : FreeSector);
+
+            // Assemble file
+            var file = new byte[SectorSize + totalSectors * SectorSize];
+            header.CopyTo(file, 0);
+            for (var i = 0; i < fatSectors; i++)
+                for (var j = 0; j < SectorSize / 4; j++)
+                    BinaryPrimitives.WriteUInt32LittleEndian(file.AsSpan(SectorSize + i * SectorSize + j * 4, 4), fat[i * (SectorSize / 4) + j]);
+            for (var i = 0; i < payloads.Count; i++)
+                payloads[i].CopyTo(file, SectorSize + (int)starts[i] * SectorSize);
+
+            return new MemoryStream(file);
+        }
+
+        private static void WriteDirEntry(byte[] dir, int index, string name, byte type,
+            uint left, uint right, uint child, uint start, uint size)
+        {
+            var off = index * 128;
+            var nameBytes = Encoding.Unicode.GetBytes(name);
+            nameBytes.CopyTo(dir, off);
+            BinaryPrimitives.WriteUInt16LittleEndian(dir.AsSpan(off + 64, 2), (ushort)(nameBytes.Length + 2));
+            dir[off + 66] = type;
+            dir[off + 67] = 1; // black
+            BinaryPrimitives.WriteUInt32LittleEndian(dir.AsSpan(off + 68, 4), left);
+            BinaryPrimitives.WriteUInt32LittleEndian(dir.AsSpan(off + 72, 4), right);
+            BinaryPrimitives.WriteUInt32LittleEndian(dir.AsSpan(off + 76, 4), child);
+            BinaryPrimitives.WriteUInt32LittleEndian(dir.AsSpan(off + 116, 4), start);
+            BinaryPrimitives.WriteUInt32LittleEndian(dir.AsSpan(off + 120, 4), size);
+        }
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/PolicyEnforcementMiddlewareTests.cs

@@ -28,6 +28,8 @@ public class PolicyEnforcementMiddlewareTests
 {
     private const string TenantA = "11111111-1111-1111-1111-111111111111";
     private const string TenantB = "22222222-2222-2222-2222-222222222222";
+    /// <summary>The oid every <see cref="AuthedPrincipal"/> carries and the default identity binding pins.</summary>
+    private const string TestOid = "aaaaaaaa-1111-1111-1111-aaaaaaaaaaaa";
 
     private sealed class Harness
     {
@@ -38,6 +40,18 @@ public class PolicyEnforcementMiddlewareTests
         public void AsGlobalRole(string role) =>
             Repo.Setup(r => r.GetGlobalRoleAsync(It.IsAny<string>())).ReturnsAsync(role);
 
+        /// <summary>
+        /// Re-homes the caller's identity binding (default: TenantA + <see cref="TestOid"/>). Cross-tenant roles
+        /// resolve ONLY for a principal whose tid/oid match this — use it for principals minted in TenantB.
+        /// </summary>
+        public void BoundTo(string tenantId, string objectId = TestOid) =>
+            Repo.Setup(r => r.GetIdentityBindingAsync(It.IsAny<string>()))
+                .ReturnsAsync(new AdminIdentityBinding
+                {
+                    TenantId = tenantId.ToLowerInvariant(),
+                    ObjectId = objectId.ToLowerInvariant(),
+                });
+
         public void AsTenantAdmin(string tenantId, string upn) =>
             Repo.Setup(r => r.GetTenantMemberAsync(It.IsAny<string>(), It.IsAny<string>()))
                 .ReturnsAsync(new TenantMember
@@ -76,6 +90,10 @@ public class PolicyEnforcementMiddlewareTests
         // No group assignments by default (delegated scope resolves direct grants + group tenants).
         repo.Setup(r => r.GetGroupAssignmentsForUpnAsync(It.IsAny<string>()))
             .ReturnsAsync(new List<TenantGroupAssignment>());
+        // Every UPN is identity-bound to TenantA + TestOid by default (matches AuthedPrincipal(TenantA, …));
+        // tests that mint the caller in TenantB re-home it via Harness.BoundTo.
+        repo.Setup(r => r.GetIdentityBindingAsync(It.IsAny<string>()))
+            .ReturnsAsync(new AdminIdentityBinding { TenantId = TenantA, ObjectId = TestOid });
 
         // Captured config repo: GetTenantConfigurationAsync returns null (tenant has no config row) so we can
         // assert that authorization role resolution never PERSISTS a default row as a side effect.
@@ -84,11 +102,14 @@ public class PolicyEnforcementMiddlewareTests
             .ReturnsAsync((TenantConfiguration?)null);
 
         var cache = new MemoryCache(new MemoryCacheOptions());
-        var globalAdmin = new GlobalAdminService(repo.Object, cache, NullLogger<GlobalAdminService>.Instance);
+        // REAL binding service on the mocked repo: the middleware tests must exercise the identity check.
+        var bindings = new AdminIdentityBindingService(repo.Object, cache, NullLogger<AdminIdentityBindingService>.Instance);
+        var globalAdmin = new GlobalAdminService(repo.Object, bindings, cache, NullLogger<GlobalAdminService>.Instance);
         // Entitlements stubbed to Enterprise — the delegated-rescue tests here pin AUTHORIZATION
         // mechanics; the Enterprise-only edition gate is covered by DelegatedAdminEditionGateTests.
         var delegatedAdmin = new DelegatedAdminService(
             repo.Object,
+            bindings,
             new StubTenantEntitlementService(AutopilotMonitor.Functions.Security.TenantEdition.Pro),
             cache,
             NullLogger<DelegatedAdminService>.Instance);
@@ -102,8 +123,8 @@ public class PolicyEnforcementMiddlewareTests
         return new Harness { Middleware = mw, Repo = repo, ConfigRepo = configRepo };
     }
 
-    private static ClaimsPrincipal AuthedPrincipal(string tenantId, string upn)
-        => new(new ClaimsIdentity(new[] { new Claim("tid", tenantId), new Claim("upn", upn) }, "TestAuth"));
+    private static ClaimsPrincipal AuthedPrincipal(string tenantId, string upn, string objectId = TestOid)
+        => new(new ClaimsIdentity(new[] { new Claim("tid", tenantId), new Claim("upn", upn), new Claim("oid", objectId) }, "TestAuth"));
 
     // ── ADDITIVE: GlobalReader + own-tenant Admin keeps IsTenantAdmin ──────────────
 
@@ -675,11 +696,13 @@ public class PolicyEnforcementMiddlewareTests
 
             var reader = BuildHarness();
             reader.AsGlobalRole(Constants.GlobalRoles.GlobalReader);
+            reader.BoundTo(TenantB);
             var readerResult = await reader.Middleware.DecideAsync(method, path, null, AuthedPrincipal(TenantB, "reader@vendor.example"));
             Assert.False(readerResult.Allowed, $"{method} {path} must deny a read-only Global Reader");
 
             var delegated = BuildHarness();
             delegated.AsDelegated(TenantA, Constants.DelegatedRoles.DelegatedAdmin);
+            delegated.BoundTo(TenantB);
             var delegatedResult = await delegated.Middleware.DecideAsync(method, path, null, AuthedPrincipal(TenantB, "msp@partner.example"));
             Assert.False(delegatedResult.Allowed, $"{method} {path} must deny a delegated (MSP) admin");
         }
@@ -713,12 +736,14 @@ public class PolicyEnforcementMiddlewareTests
 
         var reader = BuildHarness();
         reader.AsGlobalRole(Constants.GlobalRoles.GlobalReader);
+        reader.BoundTo(TenantB);
         var readerResult = await reader.Middleware.DecideAsync(
             "PATCH", $"/api/config/{TenantA}/fields", null, AuthedPrincipal(TenantB, "reader@vendor.example"));
         Assert.False(readerResult.Allowed, "read-only Global Reader must not patch config fields");
 
         var delegated = BuildHarness();
         delegated.AsDelegated(TenantA, Constants.DelegatedRoles.DelegatedAdmin);
+        delegated.BoundTo(TenantB);
         var delegatedResult = await delegated.Middleware.DecideAsync(
             "PATCH", $"/api/config/{TenantA}/fields", null, AuthedPrincipal(TenantB, "msp@partner.example"));
         Assert.False(delegatedResult.Allowed, "delegated (MSP) admin must not patch config fields");
@@ -979,6 +1004,24 @@ public class PolicyEnforcementMiddlewareTests
         Assert.Equal(403, result.StatusCode);
     }
 
+    [Fact]
+    public void PreviewNotificationEmails_PluralRoute_DoesNotResolveToPerTenantEntry()
+    {
+        // The cross-tenant address map sits one character away from the per-tenant read
+        // (notification-email/{tenantId}). If the plural path ever resolved to that entry, the
+        // middleware would demand a tenantId the route does not carry — and RouteParam scoping
+        // would hand a delegated caller a rescue path into the whole map.
+        var plural = EndpointAccessPolicyCatalog.FindPolicy("GET", "/api/preview/notification-emails");
+        Assert.NotNull(plural);
+        Assert.Equal("preview/notification-emails", plural!.RouteTemplate);
+        Assert.Equal(TenantScoping.None, plural.TenantScoping);
+
+        // …and the per-tenant route is unaffected by the new sibling.
+        var single = EndpointAccessPolicyCatalog.FindPolicy("GET", "/api/preview/notification-email/tid-1");
+        Assert.NotNull(single);
+        Assert.Equal("preview/notification-email/{tenantId}", single!.RouteTemplate);
+    }
+
     [Fact]
     public async Task GlobalReader_ExcludeDelegatedRoutes_StillAllowed()
     {
@@ -1051,6 +1094,7 @@ public class PolicyEnforcementMiddlewareTests
     [InlineData("GET", "/api/global/customs-archive/tid-1/hist-1/arc-1")]
     [InlineData("GET", "/api/global/tenants/tid-1/deletion-manifests")]
     [InlineData("GET", "/api/preview/notification-email/tid-1")]
+    [InlineData("GET", "/api/preview/notification-emails")]
     public void PlatformOperationalReads_ExcludeDelegated(string method, string path)
     {
         var entry = EndpointAccessPolicyCatalog.FindPolicy(method, path);
@@ -1174,7 +1218,10 @@ public class PolicyEnforcementMiddlewareTests
 
         Assert.True(result.Allowed);
         Assert.Equal(upn, result.Context!.UserPrincipalName);
-        Assert.Equal(upn, result.Context!.CallerId);
+        // Throttle identity prefers the oid — unique per account, so two tenants sharing a UPN string
+        // (the API accepts tokens from any tenant) no longer share a bucket.
+        Assert.Equal(TestOid, result.Context!.CallerId);
+        Assert.Equal(TestOid, result.Context!.ObjectId);
     }
 
     // ── CallerId: throttle identity survives tokens that carry no UPN ──────────────

src/Backend/AutopilotMonitor.Functions.Tests/RevokeEnforcementTests.cs

@@ -26,9 +26,20 @@ public class RevokeEnforcementTests
     private const string TenantB = "22222222-2222-2222-2222-222222222222";
     private const string GroupId = "tpl-aaaaaaaa";
 
+    private static readonly StubAdminIdentityBindingService Bindings = new(bound: true);
+
+    /// <summary>Resolver stub: never consulted by the revoke/validation seams under test (loose mock ⇒ null).</summary>
+    private static AdminIdentityResolver Resolver() =>
+        new Mock<AdminIdentityResolver>(
+            Mock.Of<IMetricsRepository>(),
+            new Mock<TenantConfigurationService>(Mock.Of<IConfigRepository>(), NullLogger<TenantConfigurationService>.Instance,
+                new MemoryCache(new MemoryCacheOptions())) { CallBase = false }.Object,
+            NullLogger<AdminIdentityResolver>.Instance) { CallBase = false }.Object;
+
     private static DelegatedAdminService BuildService(Mock<IAdminRepository> repo) =>
         new(
             repo.Object,
+            Bindings,
             new StubTenantEntitlementService(AutopilotMonitor.Functions.Security.TenantEdition.Pro),
             new MemoryCache(new MemoryCacheOptions()),
             NullLogger<DelegatedAdminService>.Instance);
@@ -55,7 +66,7 @@ public class RevokeEnforcementTests
         var audit = BuildAuditRepo();
         var signalR = new FakeSignalRNotificationService();
         var fn = new DelegatedAdminManagementFunction(
-            NullLogger<DelegatedAdminManagementFunction>.Instance, BuildService(repo), audit.Object, signalR);
+            NullLogger<DelegatedAdminManagementFunction>.Instance, BuildService(repo), Resolver(), audit.Object, signalR);
         return (fn, repo, audit, signalR);
     }
 
@@ -72,7 +83,7 @@ public class RevokeEnforcementTests
         var audit = BuildAuditRepo();
         var signalR = new FakeSignalRNotificationService();
         var fn = new TenantGroupManagementFunction(
-            NullLogger<TenantGroupManagementFunction>.Instance, BuildService(repo), audit.Object, signalR);
+            NullLogger<TenantGroupManagementFunction>.Instance, BuildService(repo), Resolver(), audit.Object, signalR);
         return (fn, repo, audit, signalR);
     }
 
@@ -101,11 +112,40 @@ public class RevokeEnforcementTests
             DelegatedAdminManagementFunction.ValidateGrantRequest(
                 new GrantDelegatedAdminRequest { Upn = Upn, TenantId = tenantId }, out _));
 
+    [Theory]
+    [InlineData("partner.example")]
+    [InlineData("11111111-1111-1111-1111")]
+    public void ValidateGrant_NonGuidHomeTenant_Rejected(string homeTenantId)
+    {
+        // The home tenant is OPTIONAL at the API (resolved from sign-in history / UPN domain when absent),
+        // but a supplied value must be a GUID — a typo must not become a binding.
+        var error = DelegatedAdminManagementFunction.ValidateGrantRequest(
+            new GrantDelegatedAdminRequest { Upn = Upn, TenantId = TenantA, HomeTenantId = homeTenantId }, out _);
+        Assert.NotNull(error);
+        Assert.Contains("homeTenantId", error);
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    public void ValidateGrant_AbsentHomeTenant_IsValid_ResolvedLater(string? homeTenantId)
+        => Assert.Null(DelegatedAdminManagementFunction.ValidateGrantRequest(
+            new GrantDelegatedAdminRequest { Upn = Upn, TenantId = TenantA, HomeTenantId = homeTenantId }, out _));
+
+    [Fact]
+    public void ValidateGrant_NonGuidObjectId_Rejected()
+    {
+        var error = DelegatedAdminManagementFunction.ValidateGrantRequest(
+            new GrantDelegatedAdminRequest { Upn = Upn, TenantId = TenantA, HomeTenantId = TenantB, ObjectId = "not-a-guid" }, out _);
+        Assert.NotNull(error);
+        Assert.Contains("objectId", error);
+    }
+
     [Fact]
     public void ValidateGrant_UnknownRole_Rejected()
     {
         var error = DelegatedAdminManagementFunction.ValidateGrantRequest(
-            new GrantDelegatedAdminRequest { Upn = Upn, TenantId = TenantA, Role = "GlobalAdmin" }, out _);
+            new GrantDelegatedAdminRequest { Upn = Upn, TenantId = TenantA, HomeTenantId = TenantB, Role = "GlobalAdmin" }, out _);
         Assert.NotNull(error);
         Assert.Contains(Constants.DelegatedRoles.DelegatedReader, error);
     }
@@ -114,7 +154,7 @@ public class RevokeEnforcementTests
     public void ValidateGrant_EmptyRole_DefaultsToLeastPrivilegedReader()
     {
         Assert.Null(DelegatedAdminManagementFunction.ValidateGrantRequest(
-            new GrantDelegatedAdminRequest { Upn = Upn, TenantId = TenantA }, out var role));
+            new GrantDelegatedAdminRequest { Upn = Upn, TenantId = TenantA, HomeTenantId = TenantB }, out var role));
         Assert.Equal(Constants.DelegatedRoles.DelegatedReader, role);
     }
 
@@ -122,7 +162,11 @@ public class RevokeEnforcementTests
     public void ValidateGrant_ExplicitDelegatedAdmin_Accepted()
     {
         Assert.Null(DelegatedAdminManagementFunction.ValidateGrantRequest(
-            new GrantDelegatedAdminRequest { Upn = Upn, TenantId = TenantA, Role = Constants.DelegatedRoles.DelegatedAdmin },
+            new GrantDelegatedAdminRequest
+            {
+                Upn = Upn, TenantId = TenantA, HomeTenantId = TenantB,
+                ObjectId = "aaaaaaaa-1111-1111-1111-aaaaaaaaaaaa", Role = Constants.DelegatedRoles.DelegatedAdmin,
+            },
             out var role));
         Assert.Equal(Constants.DelegatedRoles.DelegatedAdmin, role);
     }

src/Backend/AutopilotMonitor.Functions.Tests/SessionOwnerBindingObserverTests.cs

@@ -0,0 +1,198 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Azure.Data.Tables;
+using AutopilotMonitor.Functions.Security;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Functions.Services.Notifications;
+using AutopilotMonitor.Shared.DataAccess;
+using AutopilotMonitor.Shared.Models;
+using Microsoft.Azure.Functions.Worker.Http;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// SESSION-OWNER-BINDING-SHADOW carriers: the outcome lands on the request row for every
+/// request (denominator), non-Match outcomes produce a Warning, would-reject outcomes raise one
+/// throttled ops event, stamping is fail-soft, and nothing is ever refused.
+/// </summary>
+public class SessionOwnerBindingObserverTests
+{
+    private const string Tenant = "11111111-1111-1111-1111-111111111111";
+    private const string Session = "22222222-2222-2222-2222-222222222222";
+    private const string Thumb1 = "AA11BB22CC33DD44EE55FF6677889900AABBCCDD";
+    private const string Thumb2 = "0011223344556677889900AABBCCDDEEFF001122";
+
+    private sealed class Rig
+    {
+        public List<OpsEventEntry> Ops { get; } = new();
+        public Mock<ISessionRepository> Repo { get; } = new();
+        public CapturingLogger Logger { get; } = new();
+        public SessionOwnerBindingObserver Sut { get; }
+
+        public Rig()
+        {
+            var opsRepo = new Mock<IOpsEventRepository>();
+            opsRepo.Setup(r => r.SaveOpsEventAsync(It.IsAny<OpsEventEntry>()))
+                .Callback<OpsEventEntry>(e => { lock (Ops) Ops.Add(e); })
+                .Returns(Task.CompletedTask);
+            var adminConfig = new Mock<AdminConfigurationService>(
+                Mock.Of<IConfigRepository>(), NullLogger<AdminConfigurationService>.Instance,
+                new MemoryCache(new MemoryCacheOptions())) { CallBase = false };
+            var alertDispatch = new OpsAlertDispatchService(
+                adminConfig.Object,
+                new TelegramNotificationService(new HttpClient(), Mock.Of<IConfigRepository>(),
+                    NullLogger<TelegramNotificationService>.Instance),
+                new WebhookNotificationService(new HttpClient(), NullLogger<WebhookNotificationService>.Instance),
+                NullLogger<OpsAlertDispatchService>.Instance);
+            var opsService = new OpsEventService(opsRepo.Object, NullLogger<OpsEventService>.Instance, alertDispatch);
+
+            Sut = new SessionOwnerBindingObserver(
+                Logger, opsService, new MemoryCache(new MemoryCacheOptions()), Repo.Object);
+        }
+    }
+
+    private static (HttpRequestData Req, Dictionary<object, object> Items) Request(string agentVersion = "2.0.9999")
+    {
+        var items = new Dictionary<object, object>();
+        var contextMock = new Mock<Microsoft.Azure.Functions.Worker.FunctionContext>();
+        contextMock.SetupGet(c => c.Items).Returns(items);
+        var reqMock = new Mock<HttpRequestData>(contextMock.Object);
+        reqMock.SetupGet(r => r.Headers).Returns(new HttpHeadersCollection { { "X-Agent-Version", agentVersion } });
+        return (reqMock.Object, items);
+    }
+
+    private static SecurityValidationResult Cert(string thumb, string serial = "SN-1") => new()
+    {
+        IsValid = true, CertificateThumbprint = thumb, IntuneDeviceId = Guid.NewGuid().ToString(), SerialNumber = serial,
+    };
+
+    private static TableEntity OwnedRow(string thumb, string serial = "SN-1")
+    {
+        var row = new TableEntity(Tenant, Session) { ["SerialNumber"] = serial };
+        SessionOwnershipPolicy.ApplyTo(row, new SessionOwner
+        {
+            Kind = SessionOwner.Kinds.Cert, Thumbprint = thumb, DeviceId = Guid.NewGuid().ToString(), Serial = serial, BoundAt = DateTime.UtcNow,
+        });
+        return row;
+    }
+
+    private static async Task<List<OpsEventEntry>> SettleAsync(Rig rig, int expected)
+    {
+        // The ops event is fire-and-forget; give the continuation a moment.
+        for (var i = 0; i < 50; i++)
+        {
+            lock (rig.Ops) if (rig.Ops.Count >= expected) break;
+            await Task.Delay(20);
+        }
+        lock (rig.Ops) return rig.Ops.ToList();
+    }
+
+    [Fact]
+    public void Match_lands_on_the_request_row_and_stays_silent()
+    {
+        var rig = new Rig();
+        var (req, items) = Request();
+
+        var d = rig.Sut.Observe(req, Tenant, Session, OwnedRow(Thumb1), Cert(Thumb1), "agent/telemetry");
+
+        Assert.Equal(SessionOwnershipPolicy.Outcome.Match, d.Outcome);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.Match, items[SessionOwnershipPolicy.RequestItemKey]);
+        Assert.DoesNotContain(rig.Logger.Entries, e => e.Level == LogLevel.Warning);
+        Assert.Empty(rig.Ops);
+    }
+
+    [Fact]
+    public async Task Would_reject_outcome_warns_and_raises_one_ops_event_per_session_and_outcome()
+    {
+        var rig = new Rig();
+        var (req, items) = Request("2.0.1500");
+        var row = OwnedRow(Thumb1);
+
+        var first = rig.Sut.Observe(req, Tenant, Session, row, Cert(Thumb2, "SN-ATTACKER"), "agent/telemetry");
+        var second = rig.Sut.Observe(req, Tenant, Session, row, Cert(Thumb2, "SN-ATTACKER"), "agent/telemetry");
+
+        Assert.Equal(SessionOwnershipPolicy.Outcome.MismatchCert, first.Outcome);
+        Assert.True(first.WouldReject);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.MismatchCert, items[SessionOwnershipPolicy.RequestItemKey]);
+
+        var warnings = rig.Logger.Entries.Where(e => e.Level == LogLevel.Warning).ToList();
+        Assert.Equal(2, warnings.Count);
+        Assert.All(warnings, w => Assert.Contains("AgentSessionOwnerBinding outcome=MismatchCert enforced=False wouldReject=True", w.Message));
+        Assert.Contains("serialMatch=False", warnings[0].Message);
+        Assert.Contains("ver=2.0.1500", warnings[0].Message);
+
+        var ops = await SettleAsync(rig, 1);
+        var evt = Assert.Single(ops);
+        Assert.Equal("SessionOwnerMismatch", evt.EventType);
+        Assert.Equal(OpsEventCategory.Security, evt.Category);
+        Assert.Equal(Tenant, evt.TenantId);
+        Assert.Contains("MismatchCert", evt.Message);
+        Assert.Contains("shadow", evt.Message);
+        Assert.DoesNotContain(Thumb1, evt.Message);
+        Assert.DoesNotContain(Thumb2, evt.Message);
+        Assert.Contains("\"serialMatch\":false", evt.Details);
+        Assert.Contains("\"enforced\":false", evt.Details);
+        _ = second;
+    }
+
+    [Fact]
+    public void Rebind_warns_but_raises_no_ops_event_and_hands_back_the_owner()
+    {
+        var rig = new Rig();
+        var (req, _) = Request();
+        var row = new TableEntity(Tenant, Session) { ["SerialNumber"] = "SN-1" };
+        SessionOwnershipPolicy.ApplyTo(row, new SessionOwner { Kind = SessionOwner.Kinds.Bootstrap, BootstrapCode = "ABC123", Serial = "SN-1", BoundAt = DateTime.UtcNow });
+
+        var d = rig.Sut.Observe(req, Tenant, Session, row, Cert(Thumb1), "agent/register-session");
+
+        Assert.Equal(SessionOwnershipPolicy.Outcome.RebindBootstrapHandoff, d.Outcome);
+        Assert.NotNull(d.OwnerToStamp);
+        Assert.Contains(rig.Logger.Entries, e => e.Level == LogLevel.Warning && e.Message.Contains("wouldReject=False"));
+        Assert.Empty(rig.Ops);
+    }
+
+    [Fact]
+    public async Task Stamp_writes_the_owner_and_swallows_storage_failures()
+    {
+        var rig = new Rig();
+        rig.Repo.Setup(r => r.UpdateSessionOwnerAsync(Tenant, Session, It.IsAny<SessionOwner>()))
+            .ThrowsAsync(new InvalidOperationException("storage down"));
+        var (req, _) = Request();
+        var legacyRow = new TableEntity(Tenant, Session) { ["SerialNumber"] = "SN-1" };
+
+        var d = rig.Sut.Observe(req, Tenant, Session, legacyRow, Cert(Thumb1), "agent/telemetry");
+        Assert.Equal(SessionOwnershipPolicy.Outcome.ClaimLegacy, d.Outcome);
+
+        await rig.Sut.StampAsync(Tenant, Session, d);
+
+        rig.Repo.Verify(r => r.UpdateSessionOwnerAsync(Tenant, Session, It.Is<SessionOwner>(o => o.Thumbprint == Thumb1)), Times.Once);
+        Assert.Contains(rig.Logger.Entries, e => e.Level == LogLevel.Warning && e.Message.Contains("stamp failed"));
+    }
+
+    [Fact]
+    public async Task Stamp_is_a_no_op_without_an_owner()
+    {
+        var rig = new Rig();
+        await rig.Sut.StampAsync(Tenant, Session, new SessionOwnershipPolicy.Decision(SessionOwnershipPolicy.Outcome.Match, null, true));
+        rig.Repo.Verify(r => r.UpdateSessionOwnerAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<SessionOwner>()), Times.Never);
+    }
+
+    private sealed record LogEntry(LogLevel Level, string Message);
+
+    private sealed class CapturingLogger : ILogger<SessionOwnerBindingObserver>
+    {
+        public List<LogEntry> Entries { get; } = new();
+        public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
+        public bool IsEnabled(LogLevel logLevel) => true;
+        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception? exception, Func<TState, Exception?, string> formatter)
+            => Entries.Add(new LogEntry(logLevel, formatter(state, exception)));
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/SessionOwnershipPolicyTests.cs

@@ -0,0 +1,267 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using Azure.Data.Tables;
+using AutopilotMonitor.Functions.Security;
+using AutopilotMonitor.Shared.Models;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// SESSION-OWNER-BINDING rule matrix. The policy is pure, so every lifecycle shape that must keep
+/// working (restart, WhiteGlove Part 2, bootstrap→cert handoff, certificate re-issue, rows from
+/// before the binding) and every shape that must be visible as a would-reject (foreign cert,
+/// foreign bootstrap code, bootstrap on a cert-owned row, re-enroll without wipe) is pinned here.
+/// </summary>
+public class SessionOwnershipPolicyTests
+{
+    private static readonly DateTime Now = new(2026, 8, 29, 12, 0, 0, DateTimeKind.Utc);
+    private const string Thumb1 = "AA11BB22CC33DD44EE55FF6677889900AABBCCDD";
+    private const string Thumb2 = "0011223344556677889900AABBCCDDEEFF001122";
+    private const string Dev1 = "0f4e1c2d-1111-4aaa-8bbb-000000000001";
+    private const string Dev2 = "0f4e1c2d-2222-4aaa-8bbb-000000000002";
+
+    private static SecurityValidationResult Cert(string thumb, string? deviceId, string? serial = "SN-1") => new()
+    {
+        IsValid = true,
+        CertificateThumbprint = thumb,
+        IntuneDeviceId = deviceId,
+        SerialNumber = serial,
+        ValidatedBy = ValidatorType.AutopilotV1,
+    };
+
+    private static SecurityValidationResult Bootstrap(string code, string? serial = "SN-1") => new()
+    {
+        IsValid = true,
+        IsBootstrapAuth = true,
+        BootstrapShortCode = code,
+        SerialNumber = serial,
+        ValidatedBy = ValidatorType.Bootstrap,
+    };
+
+    private static TableEntity Row(string? serial = "SN-1", SessionOwner? owner = null)
+    {
+        var row = new TableEntity("t", "s") { ["SerialNumber"] = serial ?? string.Empty };
+        if (owner != null) SessionOwnershipPolicy.ApplyTo(row, owner);
+        return row;
+    }
+
+    private static SessionOwner CertOwner(string thumb, string? deviceId, string serial = "SN-1") =>
+        new() { Kind = SessionOwner.Kinds.Cert, Thumbprint = thumb, DeviceId = deviceId, Serial = serial, BoundAt = Now };
+
+    private static SessionOwner BootstrapOwner(string code, string serial = "SN-1") =>
+        new() { Kind = SessionOwner.Kinds.Bootstrap, BootstrapCode = code, Serial = serial, BoundAt = Now };
+
+    // ── no row / unidentified ────────────────────────────────────────────────
+
+    [Fact]
+    public void No_row_is_Fresh_and_yields_the_caller_as_owner()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(null, Cert(Thumb1, Dev1), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.Fresh, d.Outcome);
+        Assert.NotNull(d.OwnerToStamp);
+        Assert.Equal(SessionOwner.Kinds.Cert, d.OwnerToStamp!.Kind);
+        Assert.Equal(Thumb1, d.OwnerToStamp.Thumbprint);
+        Assert.Equal(Dev1, d.OwnerToStamp.DeviceId);
+        Assert.Equal("SN-1", d.OwnerToStamp.Serial);
+        Assert.False(d.WouldReject);
+    }
+
+    [Fact]
+    public void Validation_without_thumbprint_or_code_is_CallerUnidentified_and_never_rejects()
+    {
+        var v = new SecurityValidationResult { IsValid = true, SerialNumber = "SN-1" };
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: CertOwner(Thumb1, Dev1)), v, Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.CallerUnidentified, d.Outcome);
+        Assert.Null(d.OwnerToStamp);
+        Assert.False(d.WouldReject);
+    }
+
+    // ── legacy rows (pre-binding) ────────────────────────────────────────────
+
+    [Fact]
+    public void Legacy_row_with_same_serial_is_claimed()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(serial: "sn-1"), Cert(Thumb1, Dev1, "SN-1 "), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.ClaimLegacy, d.Outcome);
+        Assert.NotNull(d.OwnerToStamp);
+        Assert.True(d.SerialMatch);
+        Assert.False(d.WouldReject);
+    }
+
+    [Fact]
+    public void Legacy_row_with_different_serial_would_reject_and_is_not_claimed()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(serial: "OTHER"), Cert(Thumb1, Dev1), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.LegacySerialMismatch, d.Outcome);
+        Assert.Null(d.OwnerToStamp);
+        Assert.True(d.WouldReject);
+    }
+
+    [Fact]
+    public void Legacy_row_without_serial_cannot_be_claimed()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(serial: ""), Cert(Thumb1, Dev1), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.LegacySerialMismatch, d.Outcome);
+    }
+
+    // ── cert caller ──────────────────────────────────────────────────────────
+
+    [Fact]
+    public void Same_thumbprint_is_Match_case_insensitively()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: CertOwner(Thumb1, Dev1)), Cert(Thumb1.ToLowerInvariant(), Dev1), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.Match, d.Outcome);
+        Assert.Null(d.OwnerToStamp);
+    }
+
+    [Fact]
+    public void Reissued_certificate_of_the_same_device_rebinds()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: CertOwner(Thumb1, Dev1)), Cert(Thumb2, Dev1.ToUpperInvariant()), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.RebindCertRotation, d.Outcome);
+        Assert.Equal(Thumb2, d.OwnerToStamp!.Thumbprint);
+        Assert.Equal(Dev1, d.OwnerToStamp.DeviceId);
+        Assert.False(d.WouldReject);
+    }
+
+    [Fact]
+    public void Foreign_certificate_is_MismatchCert_with_serialMatch_false()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: CertOwner(Thumb1, Dev1)), Cert(Thumb2, Dev2, "SN-ATTACKER"), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.MismatchCert, d.Outcome);
+        Assert.False(d.SerialMatch);
+        Assert.Null(d.OwnerToStamp);
+        Assert.True(d.WouldReject);
+    }
+
+    [Fact]
+    public void Reenroll_without_wipe_is_MismatchCert_with_serialMatch_true()
+    {
+        // Same chassis (serial), new Intune device id + new certificate, old session.id on disk.
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: CertOwner(Thumb1, Dev1)), Cert(Thumb2, Dev2, "SN-1"), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.MismatchCert, d.Outcome);
+        Assert.True(d.SerialMatch);
+        Assert.True(d.WouldReject);
+    }
+
+    [Fact]
+    public void Cert_without_device_id_never_rebinds_on_thumbprint_change()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: CertOwner(Thumb1, null)), Cert(Thumb2, null), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.MismatchCert, d.Outcome);
+    }
+
+    [Fact]
+    public void Cert_on_bootstrap_owned_row_with_same_serial_is_the_handoff_and_rebinds_to_cert()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: BootstrapOwner("ABC123")), Cert(Thumb1, Dev1), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.RebindBootstrapHandoff, d.Outcome);
+        Assert.Equal(SessionOwner.Kinds.Cert, d.OwnerToStamp!.Kind);
+        Assert.Null(d.OwnerToStamp.BootstrapCode);
+        Assert.False(d.WouldReject);
+    }
+
+    [Fact]
+    public void Cert_on_bootstrap_owned_row_with_other_serial_would_reject()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: BootstrapOwner("ABC123")), Cert(Thumb1, Dev1, "OTHER"), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.MismatchBootstrapOwned, d.Outcome);
+        Assert.True(d.WouldReject);
+    }
+
+    // ── bootstrap caller ─────────────────────────────────────────────────────
+
+    [Fact]
+    public void Bootstrap_same_code_and_serial_is_Match()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: BootstrapOwner("ABC123")), Bootstrap("abc123"), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.Match, d.Outcome);
+    }
+
+    [Theory]
+    [InlineData("XYZ789", "SN-1")]
+    [InlineData("ABC123", "SN-2")]
+    public void Bootstrap_with_other_code_or_serial_would_reject(string code, string serial)
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: BootstrapOwner("ABC123")), Bootstrap(code, serial), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.MismatchBootstrap, d.Outcome);
+        Assert.True(d.WouldReject);
+    }
+
+    [Fact]
+    public void Bootstrap_on_cert_owned_row_is_a_downgrade_and_would_reject()
+    {
+        var d = SessionOwnershipPolicy.Evaluate(Row(owner: CertOwner(Thumb1, Dev1)), Bootstrap("ABC123"), Now);
+        Assert.Equal(SessionOwnershipPolicy.Outcome.DowngradeToBootstrap, d.Outcome);
+        Assert.True(d.WouldReject);
+    }
+
+    [Fact]
+    public void Bootstrap_validation_without_short_code_is_unidentified()
+    {
+        var v = new SecurityValidationResult { IsValid = true, IsBootstrapAuth = true, SerialNumber = "SN-1" };
+        Assert.Equal(SessionOwnershipPolicy.Outcome.CallerUnidentified, SessionOwnershipPolicy.Evaluate(Row(), v, Now).Outcome);
+    }
+
+    // ── row round-trip ───────────────────────────────────────────────────────
+
+    [Fact]
+    public void ApplyTo_and_FromRow_round_trip_and_clear_the_other_kind()
+    {
+        var row = Row(owner: BootstrapOwner("ABC123"));
+        SessionOwnershipPolicy.ApplyTo(row, CertOwner(Thumb1, Dev1));
+
+        Assert.False(row.ContainsKey(SessionOwner.Columns.BootstrapCode));
+        var back = SessionOwnershipPolicy.FromRow(row)!;
+        Assert.Equal(SessionOwner.Kinds.Cert, back.Kind);
+        Assert.Equal(Thumb1, back.Thumbprint);
+        Assert.Equal(Dev1, back.DeviceId);
+        Assert.Equal("SN-1", back.Serial);
+        Assert.Equal(Now, back.BoundAt);
+        Assert.Equal(DateTimeKind.Utc, back.BoundAt.Kind);
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("Unknown")]
+    public void FromRow_treats_unknown_kind_as_legacy(string? kind)
+    {
+        var row = Row();
+        if (kind != null) row[SessionOwner.Columns.Kind] = kind;
+        Assert.Null(SessionOwnershipPolicy.FromRow(row));
+    }
+
+    // ── enforcement rule pins ────────────────────────────────────────────────
+
+    [Theory]
+    [InlineData(SessionOwnershipPolicy.Outcome.Fresh)]
+    [InlineData(SessionOwnershipPolicy.Outcome.Match)]
+    [InlineData(SessionOwnershipPolicy.Outcome.ClaimLegacy)]
+    [InlineData(SessionOwnershipPolicy.Outcome.RebindCertRotation)]
+    [InlineData(SessionOwnershipPolicy.Outcome.RebindBootstrapHandoff)]
+    [InlineData(SessionOwnershipPolicy.Outcome.CallerUnidentified)]
+    public void Lifecycle_outcomes_are_deliberately_tolerated(string outcome)
+        => Assert.False(SessionOwnershipPolicy.WouldRejectUnderEnforcement(outcome));
+
+    [Theory]
+    [InlineData(SessionOwnershipPolicy.Outcome.LegacySerialMismatch)]
+    [InlineData(SessionOwnershipPolicy.Outcome.MismatchBootstrapOwned)]
+    [InlineData(SessionOwnershipPolicy.Outcome.MismatchCert)]
+    [InlineData(SessionOwnershipPolicy.Outcome.MismatchBootstrap)]
+    [InlineData(SessionOwnershipPolicy.Outcome.DowngradeToBootstrap)]
+    public void Foreign_identity_outcomes_would_reject(string outcome)
+        => Assert.True(SessionOwnershipPolicy.WouldRejectUnderEnforcement(outcome));
+
+    [Fact]
+    public void Stage1_has_no_Rejects_rule()
+    {
+        // Enforcement is a deliberate, visible code change (stage 2) — not something that can
+        // slip in through a refactor. Delete this test in the change that adds Rejects.
+        var rejects = typeof(SessionOwnershipPolicy).GetMethods(BindingFlags.Public | BindingFlags.Static)
+            .Where(m => m.Name == "Rejects").ToArray();
+        Assert.Empty(rejects);
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/StoreSessionReregistrationPreserveTests.cs

@@ -305,6 +305,84 @@ public class StoreSessionReregistrationPreserveTests
     /// try/catch in the SUT, so leaving those table clients unconfigured (null) is harmless and
     /// keeps the test focused on the Sessions Replace payload.
     /// </summary>
+    // ── SESSION-OWNER-BINDING ────────────────────────────────────────────────
+
+    [Fact]
+    public async Task StoreSessionAsync_preserves_the_owner_when_no_owner_is_stamped()
+    {
+        var existing = new TableEntity(TenantId, SessionId)
+        {
+            ["StartedAt"] = new DateTimeOffset(new DateTime(2026, 1, 1, 8, 0, 0, DateTimeKind.Utc)),
+            ["Status"] = "InProgress",
+            ["OwnerKind"] = "Cert",
+            ["OwnerThumbprint"] = "AA11BB22",
+            ["OwnerDeviceId"] = "0f4e1c2d-1111-4aaa-8bbb-000000000001",
+            ["OwnerSerial"] = "SN-1",
+            ["OwnerBoundAt"] = new DateTimeOffset(new DateTime(2026, 1, 1, 8, 0, 5, DateTimeKind.Utc)),
+        };
+        existing.ETag = new ETag("0xEXISTING");
+        var harness = new Harness(existing);
+
+        var ok = await harness.Sut.StoreSessionAsync(new SessionRegistration
+        {
+            TenantId = TenantId, SessionId = SessionId, SerialNumber = "SN-1",
+            StartedAt = new DateTime(2026, 1, 1, 9, 0, 0, DateTimeKind.Utc),
+        });
+
+        Assert.True(ok);
+        Assert.NotNull(harness.Written);
+        Assert.Equal("Cert", harness.Written!["OwnerKind"]);
+        Assert.Equal("AA11BB22", harness.Written["OwnerThumbprint"]);
+        Assert.Equal("0f4e1c2d-1111-4aaa-8bbb-000000000001", harness.Written["OwnerDeviceId"]);
+        Assert.Equal("SN-1", harness.Written["OwnerSerial"]);
+        Assert.True(harness.Written.ContainsKey("OwnerBoundAt"));
+    }
+
+    [Fact]
+    public async Task StoreSessionAsync_replaces_the_owner_when_one_is_stamped_and_clears_the_other_kind()
+    {
+        var existing = new TableEntity(TenantId, SessionId)
+        {
+            ["StartedAt"] = new DateTimeOffset(new DateTime(2026, 1, 1, 8, 0, 0, DateTimeKind.Utc)),
+            ["Status"] = "InProgress",
+            ["OwnerKind"] = "Bootstrap",
+            ["OwnerBootstrapCode"] = "ABC123",
+            ["OwnerSerial"] = "SN-1",
+            ["OwnerBoundAt"] = new DateTimeOffset(new DateTime(2026, 1, 1, 8, 0, 5, DateTimeKind.Utc)),
+        };
+        existing.ETag = new ETag("0xEXISTING");
+        var harness = new Harness(existing);
+
+        var boundAt = new DateTime(2026, 1, 1, 9, 0, 1, DateTimeKind.Utc);
+        var ok = await harness.Sut.StoreSessionAsync(new SessionRegistration
+        {
+            TenantId = TenantId, SessionId = SessionId, SerialNumber = "SN-1",
+            StartedAt = new DateTime(2026, 1, 1, 9, 0, 0, DateTimeKind.Utc),
+        }, new SessionOwner { Kind = "Cert", Thumbprint = "CC33DD44", DeviceId = "dev-1", Serial = "SN-1", BoundAt = boundAt });
+
+        Assert.True(ok);
+        Assert.Equal("Cert", harness.Written!["OwnerKind"]);
+        Assert.Equal("CC33DD44", harness.Written["OwnerThumbprint"]);
+        Assert.False(harness.Written.ContainsKey("OwnerBootstrapCode"));
+        Assert.Equal(new DateTimeOffset(boundAt), harness.Written.GetDateTimeOffset("OwnerBoundAt"));
+    }
+
+    [Fact]
+    public async Task StoreSessionAsync_fresh_row_carries_the_stamped_owner()
+    {
+        var harness = new Harness(existing: null);
+        var ok = await harness.Sut.StoreSessionAsync(new SessionRegistration
+        {
+            TenantId = TenantId, SessionId = SessionId, SerialNumber = "SN-1",
+            StartedAt = new DateTime(2026, 1, 1, 9, 0, 0, DateTimeKind.Utc),
+        }, new SessionOwner { Kind = "Bootstrap", BootstrapCode = "ABC123", Serial = "SN-1", BoundAt = DateTime.UtcNow });
+
+        Assert.True(ok);
+        Assert.Equal("Bootstrap", harness.Written!["OwnerKind"]);
+        Assert.Equal("ABC123", harness.Written["OwnerBootstrapCode"]);
+        Assert.False(harness.Written.ContainsKey("OwnerThumbprint"));
+    }
+
     private sealed class Harness
     {
         public Mock<TableClient> Sessions { get; }

src/Backend/AutopilotMonitor.Functions.Tests/StubAdminIdentityBindingService.cs

@@ -0,0 +1,54 @@
+using AutopilotMonitor.Functions.Security;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.DataAccess;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Test stub for <see cref="AdminIdentityBindingService"/> — answers the identity-binding check with a
+/// fixed verdict and records grant-time bindings in memory, without any storage dependency. Used wherever
+/// a service under test consumes the binding check but the test's subject is something else (row/role
+/// resolution, the entitlement gate, revoke enforcement). The binding logic itself is pinned by
+/// <see cref="AdminIdentityBindingServiceTests"/>; the end-to-end authorization effect by
+/// <see cref="AdminIdentityBindingAuthorizationTests"/>.
+/// </summary>
+internal sealed class StubAdminIdentityBindingService : AdminIdentityBindingService
+{
+    private readonly Func<AdminIdentity?, bool> _verdict;
+
+    /// <summary>Every (upn, tenantId, objectId) passed to EnsureBoundAsync / RebindAsync, in call order.</summary>
+    public List<(string Upn, string TenantId, string? ObjectId)> Bindings { get; } = new();
+
+    public StubAdminIdentityBindingService(bool bound = true) : this(_ => bound)
+    {
+    }
+
+    public StubAdminIdentityBindingService(Func<AdminIdentity?, bool> verdict)
+        : base(Mock.Of<IAdminRepository>(), new MemoryCache(new MemoryCacheOptions()),
+            NullLogger<AdminIdentityBindingService>.Instance)
+    {
+        _verdict = verdict;
+    }
+
+    public override Task<bool> IsBoundAsync(AdminIdentity? identity) => Task.FromResult(_verdict(identity));
+
+    public override Task<AdminIdentityBinding> EnsureBoundAsync(string upn, string tenantId, string? objectId, string boundBy)
+    {
+        Bindings.Add((upn.ToLowerInvariant(), tenantId.ToLowerInvariant(), objectId?.ToLowerInvariant()));
+        return Task.FromResult(new AdminIdentityBinding
+        {
+            Upn = upn.ToLowerInvariant(),
+            TenantId = tenantId.ToLowerInvariant(),
+            ObjectId = objectId?.ToLowerInvariant() ?? string.Empty,
+            BoundBy = boundBy,
+        });
+    }
+
+    public override Task<AdminIdentityBinding> RebindAsync(string upn, string tenantId, string? objectId, string boundBy)
+        => EnsureBoundAsync(upn, tenantId, objectId, boundBy);
+
+    public override Task RemoveAsync(string upn) => Task.CompletedTask;
+}

src/Backend/AutopilotMonitor.Functions.Tests/TenantApprovalServiceTests.cs

@@ -22,6 +22,7 @@ public class TenantApprovalServiceTests
     private readonly Mock<PreviewWhitelistService> _previewMock;
     private readonly Mock<TenantConfigurationService> _tenantConfigMock;
     private readonly Mock<IEmailService> _emailMock;
+    private readonly List<OpsEventEntry> _opsEvents = new();
     private readonly TenantApprovalService _sut;
 
     public TenantApprovalServiceTests()
@@ -40,7 +41,23 @@ public class TenantApprovalServiceTests
         _emailMock = new Mock<IEmailService>();
         _emailMock.Setup(x => x.SendPreviewApprovedEmailAsync(
                 It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(true);
+
+        // Real OpsEventService over a capturing repository: its Record* helpers are not virtual,
+        // so the assertions below read the entries the service actually composes.
+        var opsRepo = new Mock<IOpsEventRepository>();
+        opsRepo.Setup(r => r.SaveOpsEventAsync(It.IsAny<OpsEventEntry>()))
+            .Callback<OpsEventEntry>(e => { lock (_opsEvents) _opsEvents.Add(e); })
             .Returns(Task.CompletedTask);
+        var adminConfig = new Mock<AdminConfigurationService>(
+            configRepo, NullLogger<AdminConfigurationService>.Instance, cache);
+        var alertDispatch = new OpsAlertDispatchService(
+            adminConfig.Object,
+            new TelegramNotificationService(new HttpClient(), configRepo,
+                NullLogger<TelegramNotificationService>.Instance),
+            new WebhookNotificationService(new HttpClient(),
+                NullLogger<WebhookNotificationService>.Instance),
+            NullLogger<OpsAlertDispatchService>.Instance);
 
         _sut = new TenantApprovalService(
             NullLogger<TenantApprovalService>.Instance,
@@ -48,7 +65,21 @@ public class TenantApprovalServiceTests
             _tenantConfigMock.Object,
             new Mock<TenantAdminsService>(
                 Mock.Of<IAdminRepository>(), cache, NullLogger<TenantAdminsService>.Instance).Object,
-            _emailMock.Object);
+            _emailMock.Object,
+            new OpsEventService(opsRepo.Object, NullLogger<OpsEventService>.Instance, alertDispatch));
+    }
+
+    private OpsEventEntry? OpsEventOfType(string eventType)
+    {
+        lock (_opsEvents) return _opsEvents.FirstOrDefault(e => e.EventType == eventType);
+    }
+
+    private static TenantConfiguration ConfigWith(string? contactEmail, string domainName = "contoso.com")
+    {
+        var config = TenantConfiguration.CreateDefault(TenantId);
+        config.DomainName = domainName;
+        config.ContactEmail = contactEmail;
+        return config;
     }
 
     [Fact]
@@ -87,15 +118,87 @@ public class TenantApprovalServiceTests
     // permanently suppress the mail), and a lost marker race must not send.
 
     [Fact]
-    public async Task TrySendWelcomeEmail_NoAddressYet_DefersWithoutConsumingMarker()
+    public async Task TrySendWelcomeEmail_NoAddressAnywhere_DefersWithoutConsumingMarker_AndRecordsSkip()
     {
         _previewMock.Setup(x => x.GetNotificationEmailAsync(TenantId)).ReturnsAsync((string?)null);
+        _tenantConfigMock.Setup(x => x.GetConfigurationAsync(TenantId)).ReturnsAsync(ConfigWith(contactEmail: null));
 
         var sent = await _sut.TrySendWelcomeEmailAsync(TenantId);
 
         Assert.False(sent);
         _previewMock.Verify(x => x.TryMarkWelcomeEmailSentAsync(It.IsAny<string>()), Times.Never);
         _emailMock.Verify(x => x.SendPreviewApprovedEmailAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()), Times.Never);
+
+        // The silent skip is exactly what hid the August 2026 outage — it must leave a record.
+        var skipped = OpsEventOfType("WelcomeEmailSkipped");
+        Assert.NotNull(skipped);
+        Assert.Equal(OpsEventSeverity.Warning, skipped!.Severity);
+        Assert.Equal(TenantId, skipped.TenantId);
+    }
+
+    [Fact]
+    public async Task TrySendWelcomeEmail_NoActivationAddress_FallsBackToTenantContactAddress()
+    {
+        _previewMock.Setup(x => x.GetNotificationEmailAsync(TenantId)).ReturnsAsync((string?)null);
+        _previewMock.Setup(x => x.TryMarkWelcomeEmailSentAsync(TenantId)).ReturnsAsync(true);
+        _tenantConfigMock.Setup(x => x.GetConfigurationAsync(TenantId))
+            .ReturnsAsync(ConfigWith(contactEmail: "contact@contoso.com"));
+
+        var sent = await _sut.TrySendWelcomeEmailAsync(TenantId);
+
+        Assert.True(sent);
+        _emailMock.Verify(x => x.SendPreviewApprovedEmailAsync("contact@contoso.com", "contoso.com", It.IsAny<CancellationToken>()), Times.Once);
+        Assert.Null(OpsEventOfType("WelcomeEmailSkipped"));
+        Assert.Contains("tenant contact address", OpsEventOfType("WelcomeEmailSent")!.Message);
+    }
+
+    [Fact]
+    public async Task TrySendWelcomeEmail_ActivationAddressWinsOverContactAddress()
+    {
+        _previewMock.Setup(x => x.GetNotificationEmailAsync(TenantId)).ReturnsAsync("chosen@contoso.com");
+        _previewMock.Setup(x => x.TryMarkWelcomeEmailSentAsync(TenantId)).ReturnsAsync(true);
+        _tenantConfigMock.Setup(x => x.GetConfigurationAsync(TenantId))
+            .ReturnsAsync(ConfigWith(contactEmail: "contact@contoso.com"));
+
+        Assert.True(await _sut.TrySendWelcomeEmailAsync(TenantId));
+
+        _emailMock.Verify(x => x.SendPreviewApprovedEmailAsync("chosen@contoso.com", "contoso.com", It.IsAny<CancellationToken>()), Times.Once);
+        Assert.Contains("activation page", OpsEventOfType("WelcomeEmailSent")!.Message);
+    }
+
+    [Fact]
+    public async Task TrySendWelcomeEmail_SignupUpnIsNeverAFallback()
+    {
+        // Admin UPNs frequently have no mailbox; bouncing them costs sender reputation for
+        // every other tenant. Only the two deliberate addresses may be used.
+        var config = ConfigWith(contactEmail: null);
+        config.OnboardedBy = "adm.someone@contoso.com";
+        _previewMock.Setup(x => x.GetNotificationEmailAsync(TenantId)).ReturnsAsync((string?)null);
+        _tenantConfigMock.Setup(x => x.GetConfigurationAsync(TenantId)).ReturnsAsync(config);
+
+        Assert.False(await _sut.TrySendWelcomeEmailAsync(TenantId));
+
+        _emailMock.Verify(x => x.SendPreviewApprovedEmailAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task TrySendWelcomeEmail_ProviderRefused_ReleasesMarker_AndRecordsFailure()
+    {
+        _previewMock.Setup(x => x.GetNotificationEmailAsync(TenantId)).ReturnsAsync("it@contoso.com");
+        _previewMock.Setup(x => x.TryMarkWelcomeEmailSentAsync(TenantId)).ReturnsAsync(true);
+        _tenantConfigMock.Setup(x => x.GetConfigurationAsync(TenantId)).ReturnsAsync(ConfigWith(contactEmail: null));
+        _emailMock.Setup(x => x.SendPreviewApprovedEmailAsync(
+                It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(false);
+
+        var sent = await _sut.TrySendWelcomeEmailAsync(TenantId);
+
+        Assert.False(sent);
+        // The marker records delivery, not an attempt — a refused send must stay retryable.
+        _previewMock.Verify(x => x.ClearWelcomeEmailSentMarkerAsync(TenantId), Times.Once);
+        var failed = OpsEventOfType("WelcomeEmailFailed");
+        Assert.NotNull(failed);
+        Assert.Equal(OpsEventSeverity.Error, failed!.Severity);
     }
 
     [Fact]
@@ -118,6 +221,7 @@ public class TenantApprovalServiceTests
     {
         _previewMock.Setup(x => x.GetNotificationEmailAsync(TenantId)).ReturnsAsync("it@contoso.com");
         _previewMock.Setup(x => x.TryMarkWelcomeEmailSentAsync(TenantId)).ReturnsAsync(false);
+        _tenantConfigMock.Setup(x => x.GetConfigurationAsync(TenantId)).ReturnsAsync(ConfigWith(contactEmail: null));
 
         var sent = await _sut.TrySendWelcomeEmailAsync(TenantId);
 
@@ -131,6 +235,7 @@ public class TenantApprovalServiceTests
         _previewMock.Setup(x => x.GetNotificationEmailAsync(TenantId)).ReturnsAsync("it@contoso.com");
         _previewMock.Setup(x => x.TryMarkWelcomeEmailSentAsync(TenantId))
             .ThrowsAsync(new InvalidOperationException("storage down"));
+        _tenantConfigMock.Setup(x => x.GetConfigurationAsync(TenantId)).ReturnsAsync(ConfigWith(contactEmail: null));
 
         var sent = await _sut.TrySendWelcomeEmailAsync(TenantId);
 

src/Backend/AutopilotMonitor.Functions.Tests/TenantAutoApproveHandlerTests.cs

@@ -44,15 +44,6 @@ public class TenantAutoApproveHandlerTests
             configRepo, cache, NullLogger<PreviewWhitelistService>.Instance, _tenantConfigMock.Object)
         { CallBase = false };
 
-        _approvalMock = new Mock<TenantApprovalService>(
-            NullLogger<TenantApprovalService>.Instance,
-            _previewMock.Object,
-            _tenantConfigMock.Object,
-            new Mock<TenantAdminsService>(
-                Mock.Of<IAdminRepository>(), cache, NullLogger<TenantAdminsService>.Instance).Object,
-            Mock.Of<IEmailService>())
-        { CallBase = false };
-
         var opsRepo = new Mock<IOpsEventRepository>();
         opsRepo.Setup(r => r.SaveOpsEventAsync(It.IsAny<OpsEventEntry>()))
             .Callback<OpsEventEntry>(e => { lock (_savedOpsEvents) _savedOpsEvents.Add(e); })
@@ -66,6 +57,16 @@ public class TenantAutoApproveHandlerTests
             NullLogger<OpsAlertDispatchService>.Instance);
         var opsService = new OpsEventService(opsRepo.Object, NullLogger<OpsEventService>.Instance, alertDispatch);
 
+        _approvalMock = new Mock<TenantApprovalService>(
+            NullLogger<TenantApprovalService>.Instance,
+            _previewMock.Object,
+            _tenantConfigMock.Object,
+            new Mock<TenantAdminsService>(
+                Mock.Of<IAdminRepository>(), cache, NullLogger<TenantAdminsService>.Instance).Object,
+            Mock.Of<IEmailService>(),
+            opsService)
+        { CallBase = false };
+
         _sut = new TenantAutoApproveHandler(
             NullLogger<TenantAutoApproveHandler>.Instance,
             _adminConfigMock.Object,

src/Backend/AutopilotMonitor.Functions.Tests/TenantConfigPatchServiceTests.cs

@@ -1,11 +1,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
 using AutopilotMonitor.Functions.DataAccess.TableStorage;
 using AutopilotMonitor.Functions.Functions.Admin;
 using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Functions.Services.Notifications;
 using AutopilotMonitor.Shared;
 using AutopilotMonitor.Shared.DataAccess;
 using AutopilotMonitor.Shared.Models;
@@ -35,6 +37,8 @@ public class TenantConfigPatchServiceTests
         public Mock<IConfigRepository> Repo { get; } = new();
         public Mock<IConfigBackupRepository> Backup { get; } = new();
         public Mock<IMaintenanceRepository> Maintenance { get; } = new();
+        public Mock<IOpsEventRepository> OpsRepo { get; } = new();
+        public List<OpsEventEntry> OpsEvents { get; } = new();
         public TenantConfigPatchService Sut { get; }
 
         public TenantConfiguration? Current;
@@ -89,8 +93,23 @@ public class TenantConfigPatchServiceTests
                 Repo.Object, NullLogger<TenantConfigurationService>.Instance,
                 new MemoryCache(new MemoryCacheOptions()));
 
+            OpsRepo.Setup(r => r.SaveOpsEventAsync(It.IsAny<OpsEventEntry>()))
+                .Callback<OpsEventEntry>(e => { lock (OpsEvents) OpsEvents.Add(e); })
+                .Returns(Task.CompletedTask);
+            var adminConfig = new Mock<AdminConfigurationService>(
+                Mock.Of<IConfigRepository>(), NullLogger<AdminConfigurationService>.Instance,
+                new MemoryCache(new MemoryCacheOptions())) { CallBase = false };
+            var alertDispatch = new OpsAlertDispatchService(
+                adminConfig.Object,
+                new TelegramNotificationService(new HttpClient(), Mock.Of<IConfigRepository>(),
+                    NullLogger<TelegramNotificationService>.Instance),
+                new WebhookNotificationService(new HttpClient(),
+                    NullLogger<WebhookNotificationService>.Instance),
+                NullLogger<OpsAlertDispatchService>.Instance);
+            var opsService = new OpsEventService(OpsRepo.Object, NullLogger<OpsEventService>.Instance, alertDispatch);
+
             Sut = new TenantConfigPatchService(
-                Repo.Object, Backup.Object, configService, Maintenance.Object,
+                Repo.Object, Backup.Object, configService, Maintenance.Object, opsService,
                 NullLogger<TenantConfigPatchService>.Instance);
         }
 
@@ -116,6 +135,41 @@ public class TenantConfigPatchServiceTests
         return o;
     }
 
+    // ── Ops visibility: Collect Logs capability flip ────────────────────────
+
+    [Fact]
+    public async Task Patch_EnablingDiagnosticsUpload_EmitsOpsEvent_OnlyOnTheFlip()
+    {
+        var stored = Stored();
+        stored.DiagnosticsUploadMode = "Off";
+        var harness = new Harness(stored);
+
+        // Settings page / MCP: turn the capability on (mode + Hosted destination).
+        var on = await harness.Sut.ApplyFieldPatchAsync(
+            TenantId, Fields(("diagnosticsUploadMode", "OnFailure"), ("diagnosticsUploadDestination", "Hosted")),
+            Ga, "mcp-patch", "enable collect logs");
+        Assert.True(on.Success, on.Error);
+
+        var enabled = Assert.Single(harness.OpsEvents);
+        Assert.Equal("DiagnosticsUploadEnabled", enabled.EventType);
+        Assert.Equal(TenantId, enabled.TenantId);
+        Assert.Contains("contoso.com", enabled.Message);
+        Assert.Contains("mcp-patch", enabled.Message);
+
+        // A further edit that keeps it on is not a flip.
+        var tweak = await harness.Sut.ApplyFieldPatchAsync(
+            TenantId, Fields(("diagnosticsUploadMode", "Always")), Ga, "mcp-patch", null);
+        Assert.True(tweak.Success, tweak.Error);
+        Assert.Single(harness.OpsEvents);
+
+        // Turning it off is the opposite flip.
+        var off = await harness.Sut.ApplyFieldPatchAsync(
+            TenantId, Fields(("diagnosticsUploadMode", "Off")), Ga, "mcp-patch", null);
+        Assert.True(off.Success, off.Error);
+        Assert.Equal(2, harness.OpsEvents.Count);
+        Assert.Equal("DiagnosticsUploadDisabled", harness.OpsEvents[1].EventType);
+    }
+
     // ── Happy path ──────────────────────────────────────────────────────────
 
     [Fact]

src/Backend/AutopilotMonitor.Functions.Tests/VerdictCalibrationRadarTests.cs

@@ -89,10 +89,79 @@ public class VerdictCalibrationRadarTests
     }
 
     [Fact]
-    public void Derived_legacy_paths_never_alert()
+    public void Derived_legacy_paths_never_alert_per_path_but_feed_the_group_sums()
     {
         var rows = Horizon(w => new[] { ("legacy:r6", "Incomplete", w ? 10 : 1), ("agent:complete", "Succeeded", w ? 10 : 19) });
-        Assert.DoesNotContain(VerdictCalibrationRadar.Evaluate(rows, Target), f => f.Kind == VerdictCalibrationAlertKinds.ShareRegression);
+        var findings = VerdictCalibrationRadar.Evaluate(rows, Target);
+        Assert.DoesNotContain(findings, f => f.Kind == VerdictCalibrationAlertKinds.ShareRegression);
+        // Legacy continuity: the rule-shaped legacy subset counts into the silence group, so a
+        // real silence jump stays visible even when the history predates the instrumentation.
+        Assert.Contains(findings, f => f.Kind == VerdictCalibrationAlertKinds.SilenceShareRegression);
+    }
+
+    [Fact]
+    public void Share_regression_requires_an_established_baseline()
+    {
+        // The 2026-08-23 instrumentation-cutover shape: the same decisions exist only under the
+        // legacy name in the baseline and only under the new name in the window. Zero baseline
+        // hits is new vocabulary, not a regression — and the legacy continuity keeps the silence
+        // group flat across the rename (production fired a lift-124 artifact without both).
+        var rows = Horizon(w => new[]
+        {
+            ("sweep:r5_incomplete", "Incomplete", w ? 4 : 0),
+            ("legacy:r5_incomplete", "Incomplete", w ? 0 : 4),
+            ("agent:complete", "Succeeded", 16),
+        });
+        var findings = VerdictCalibrationRadar.Evaluate(rows, Target);
+        Assert.DoesNotContain(findings, f => f.Kind == VerdictCalibrationAlertKinds.ShareRegression);
+        Assert.DoesNotContain(findings, f => f.Kind == VerdictCalibrationAlertKinds.SilenceShareRegression);
+    }
+
+    [Fact]
+    public void Share_regression_needs_ten_window_hits()
+    {
+        // 7 window hits at 5% vs an established 1.07% baseline — lift ~4.7, but verdict shares
+        // on single-digit counts are noise (a 3-hit episode survived as such, read 2026-08-27).
+        var rows = new List<VerdictCalibrationDailyAggregate>();
+        for (var i = 34; i >= 0; i--)
+        {
+            var inWindow = i < 7;
+            rows.Add(new VerdictCalibrationDailyAggregate
+            {
+                TenantId = "t", Date = Target.AddDays(-i).ToString("yyyy-MM-dd"), SessionCount = 20, TerminalSessionCount = 20,
+                Buckets =
+                {
+                    new VerdictCalibrationBucket { VerdictPath = "sweep:r6", Status = "Incomplete", Count = inWindow ? 1 : (i == 20 ? 6 : 0) },
+                    new VerdictCalibrationBucket { VerdictPath = "agent:complete", Status = "Succeeded", Count = inWindow ? 19 : 20 },
+                },
+            });
+        }
+        Assert.DoesNotContain(VerdictCalibrationRadar.Evaluate(rows, Target),
+            f => f.Kind == VerdictCalibrationAlertKinds.ShareRegression);
+    }
+
+    [Fact]
+    public void ReArm_clears_episodes_below_the_fire_floors()
+    {
+        // A zero-baseline episode from before the floors existed (rename artifact) clears itself
+        // even while its share is elevated…
+        var artifact = new VerdictCalibrationAlert { Kind = VerdictCalibrationAlertKinds.ShareRegression, VerdictPath = "sweep:r5_incomplete", Status = "Incomplete" };
+        var renamed = Horizon(w => new[]
+        {
+            ("sweep:r5_incomplete", "Incomplete", w ? 4 : 0),
+            ("legacy:r5_incomplete", "Incomplete", w ? 0 : 4),
+            ("agent:complete", "Succeeded", 16),
+        });
+        Assert.True(VerdictCalibrationRadar.ShouldReArm(artifact, renamed, Target));
+
+        // …and so does one whose window has shrunk under the 10-hit floor.
+        var shrunk = new VerdictCalibrationAlert { Kind = VerdictCalibrationAlertKinds.ShareRegression, VerdictPath = "maxlife:r5_awaiting", Status = "AwaitingUser" };
+        var tiny = Horizon(w => new[]
+        {
+            ("maxlife:r5_awaiting", "AwaitingUser", 1),
+            ("agent:complete", "Succeeded", 19),
+        });
+        Assert.True(VerdictCalibrationRadar.ShouldReArm(shrunk, tiny, Target));
     }
 
     [Fact]

src/Backend/AutopilotMonitor.Functions.Tests/VerdictPathTests.cs

@@ -60,6 +60,7 @@ public class VerdictPathTests
         Assert.Equal("sweep:r5_incomplete", path);
         Assert.Equal("sweep", VerdictPaths.Origin(path));
         Assert.True(VerdictPaths.IsClassifierPath(path));
+        Assert.True(VerdictPaths.IsClassifierPath("sweep:r5_assumed"));
         Assert.True(VerdictPaths.IsClassifierPath("maxlife:r1"));
         Assert.True(VerdictPaths.IsClassifierPath("late:r4"));
         Assert.True(VerdictPaths.IsClassifierPath("retro:r6"));
@@ -107,6 +108,7 @@ public class VerdictPathTests
         Assert.Equal(ClassifierRules.R3EmergencyBreak, RuleOf(new[] { Esp(DeviceSetup44), Evt("agent_emergency_break") }));
         Assert.Equal(ClassifierRules.R4DesktopHello, RuleOf(new[] { Esp(DeviceSetup44), Evt("desktop_arrived"), Evt("hello_provisioning_completed") }));
         Assert.Equal(ClassifierRules.R5DeviceSetupAwaiting, RuleOf(new[] { Esp(DeviceSetup44), Esp(AccountSetup15) }, hours: 6, grace: 72));
+        Assert.Equal(ClassifierRules.R5DesktopAssumed, RuleOf(new[] { Esp(DeviceSetup44), Esp(AccountSetup15), Evt("desktop_arrived") }, hours: 80, grace: 72));
         Assert.Equal(ClassifierRules.R5DeviceSetupIncomplete, RuleOf(new[] { Esp(DeviceSetup44), Esp(AccountSetup15) }, hours: 80, grace: 72));
         Assert.Equal(ClassifierRules.R6Fallthrough, RuleOf(Array.Empty<EnrollmentEvent>()));
     }

src/Backend/AutopilotMonitor.Functions.Tests/VulnerabilityReportEventSequenceTests.cs

@@ -115,7 +115,7 @@ public class VulnerabilityReportEventSequenceTests
         Assert.Equal("vulnerability_report", evt.EventType);
         Assert.Equal(AutopilotMonitor.Shared.Constants.EventTypes.VulnerabilityReport, evt.EventType);
         Assert.Equal("VulnerabilityCorrelationService", evt.Source);
-        Assert.Equal(EventSeverity.Error, evt.Severity); // risk=high → Error
+        Assert.Equal(EventSeverity.Warning, evt.Severity); // risk=high → Warning (severity is capped)
         // Non-phase event: must stay Unknown so the UI timeline doesn't render a phantom phase boundary.
         Assert.Equal(EnrollmentPhase.Unknown, evt.Phase);
         Assert.Equal(NowUtc, evt.Timestamp);
@@ -127,6 +127,35 @@ public class VulnerabilityReportEventSequenceTests
         Assert.IsType<Dictionary<string, object>>(evt.Data["scan_summary"]);
     }
 
+    [Theory]
+    // The scan reports on the software inventory, not on the enrollment: a finding is never an
+    // enrollment failure, so severity is capped at Warning. Error/Critical would put the report
+    // into the diagnosis page's failure evidence and into MCP's failure-intent ranking.
+    [InlineData("critical", EventSeverity.Warning)]
+    [InlineData("high",     EventSeverity.Warning)]
+    [InlineData("medium",   EventSeverity.Info)]
+    [InlineData("low",      EventSeverity.Info)]
+    [InlineData("none",     EventSeverity.Info)]
+    [InlineData("HIGH",     EventSeverity.Warning)]  // case-insensitive
+    [InlineData("",         EventSeverity.Info)]
+    public void Severity_IsCappedAtWarning(string risk, EventSeverity expected)
+    {
+        var evt = Build(null, new List<EnrollmentEvent>(), Report(risk));
+
+        Assert.Equal(expected, evt.Severity);
+    }
+
+    [Fact]
+    public void Severity_IsInfo_WhenRiskIsMissing()
+    {
+        var report = new Dictionary<string, object>
+        {
+            ["scan_summary"] = new Dictionary<string, object>(),
+        };
+
+        Assert.Equal(EventSeverity.Info, Build(null, new List<EnrollmentEvent>(), report).Severity);
+    }
+
     [Fact]
     public void Data_Phase_CarriesTheLabel()
     {

src/Backend/AutopilotMonitor.Functions.Tests/VulnerabilitySummaryAggregatorTests.cs

@@ -48,6 +48,25 @@ public class VulnerabilitySummaryAggregatorTests
         Assert.Equal(1, r.DistinctCves);
     }
 
+    [Fact]
+    public void TopCve_CarriesMaxEpssAndHighestPriority_NullWhenNothingScored()
+    {
+        var scored = Row("CVE-E", "s1", "Medium", 5.0); scored.EpssScore = 0.12; scored.Priority = "attend";
+        var scoredLower = Row("CVE-E", "s2", "Medium", 5.0); scoredLower.EpssScore = 0.03; scoredLower.Priority = "track";
+        var legacy = Row("CVE-E", "s3", "Medium", 5.0); // pre-EPSS row: null score, empty priority
+        var unscored = Row("CVE-U", "s1", "Low", 2.0);
+
+        var r = VulnerabilitySummaryAggregator.Aggregate(new[] { scored, scoredLower, legacy, unscored }, false, 20, 30, false, Now);
+
+        var e = r.TopCves.Single(c => c.CveId == "CVE-E");
+        Assert.Equal(0.12, e.EpssScore);
+        Assert.Equal("attend", e.Priority);
+
+        var u = r.TopCves.Single(c => c.CveId == "CVE-U");
+        Assert.Null(u.EpssScore);
+        Assert.Equal("", u.Priority);
+    }
+
     [Fact]
     public void BuildsSeverityBreakdownByDistinctCveAndCountsKev()
     {

src/Backend/AutopilotMonitor.Functions/DataAccess/TableStorage/TableAdminRepository.cs

@@ -19,6 +19,7 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
         private readonly TableClient _delegatedAdminsTableClient;
         private readonly TableClient _tenantGroupsTableClient;
         private readonly TableClient _tenantGroupAssignmentsTableClient;
+        private readonly TableClient _identityBindingsTableClient;
         private readonly ILogger<TableAdminRepository> _logger;
 
         public TableAdminRepository(
@@ -32,6 +33,7 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
             _delegatedAdminsTableClient = storage.GetTableClient(Constants.TableNames.DelegatedAdmins);
             _tenantGroupsTableClient = storage.GetTableClient(Constants.TableNames.TenantGroups);
             _tenantGroupAssignmentsTableClient = storage.GetTableClient(Constants.TableNames.TenantGroupAssignments);
+            _identityBindingsTableClient = storage.GetTableClient(Constants.TableNames.AdminIdentityBindings);
         }
 
         // --- Global Admins ---
@@ -670,6 +672,112 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
             return entries;
         }
 
+        // --- Admin identity bindings ---
+
+        public async Task<AdminIdentityBinding?> GetIdentityBindingAsync(string upn)
+        {
+            if (string.IsNullOrWhiteSpace(upn))
+                return null;
+
+            try
+            {
+                var result = await _identityBindingsTableClient.GetEntityAsync<AdminIdentityBindingEntity>(
+                    AdminIdentityBindingEntity.Partition, upn.ToLowerInvariant());
+                return result.Value == null ? null : MapToBinding(result.Value);
+            }
+            catch (RequestFailedException ex) when (ex.Status == 404)
+            {
+                return null;
+            }
+            // Any other storage failure propagates: the callers treat "unknown binding" as no role, so a
+            // swallowed error here would only turn an outage into a silent, confusing 403.
+        }
+
+        public async Task<List<AdminIdentityBinding>> GetAllIdentityBindingsAsync()
+        {
+            var bindings = new List<AdminIdentityBinding>();
+            await foreach (var entity in _identityBindingsTableClient.QueryAsync<AdminIdentityBindingEntity>(
+                filter: $"PartitionKey eq '{AdminIdentityBindingEntity.Partition}'"))
+            {
+                bindings.Add(MapToBinding(entity));
+            }
+            return bindings;
+        }
+
+        public async Task<bool> UpsertIdentityBindingAsync(string upn, string tenantId, string? objectId, string boundBy)
+        {
+            var now = DateTime.UtcNow;
+            var pinned = !string.IsNullOrWhiteSpace(objectId);
+            var entity = new AdminIdentityBindingEntity
+            {
+                PartitionKey = AdminIdentityBindingEntity.Partition,
+                RowKey = upn.ToLowerInvariant(),
+                Upn = upn.ToLowerInvariant(),
+                TenantId = tenantId.ToLowerInvariant(),
+                ObjectId = pinned ? objectId!.ToLowerInvariant() : string.Empty,
+                BoundBy = boundBy?.ToLowerInvariant() ?? string.Empty,
+                BoundDate = now,
+                ObjectIdPinnedDate = pinned ? now : null
+            };
+            // Replace (not merge): a rebind must drop a previously pinned object id, never inherit it.
+            await _identityBindingsTableClient.UpsertEntityAsync(entity, TableUpdateMode.Replace);
+            return true;
+        }
+
+        public async Task<AdminIdentityBinding?> TryPinIdentityObjectIdAsync(string upn, string tenantId, string objectId)
+        {
+            upn = upn.ToLowerInvariant();
+            try
+            {
+                var result = await _identityBindingsTableClient.GetEntityAsync<AdminIdentityBindingEntity>(
+                    AdminIdentityBindingEntity.Partition, upn);
+                var entity = result.Value;
+                if (entity == null)
+                    return null;
+
+                // Pin only onto an unpinned binding homed in the caller's tenant; anything else is returned
+                // untouched so the caller's verdict (mismatch) is based on what is actually stored.
+                if (!string.IsNullOrEmpty(entity.ObjectId)
+                    || !string.Equals(entity.TenantId, tenantId, StringComparison.OrdinalIgnoreCase))
+                    return MapToBinding(entity);
+
+                entity.ObjectId = objectId.ToLowerInvariant();
+                entity.ObjectIdPinnedDate = DateTime.UtcNow;
+                // ETag-conditional: if another instance pinned concurrently (412), re-read and let the
+                // caller compare against whatever won — never overwrite a competing pin.
+                await _identityBindingsTableClient.UpdateEntityAsync(entity, entity.ETag, TableUpdateMode.Replace);
+                return MapToBinding(entity);
+            }
+            catch (RequestFailedException ex) when (ex.Status == 404)
+            {
+                return null;
+            }
+            catch (RequestFailedException ex) when (ex.Status == 412)
+            {
+                _logger.LogWarning("[IdentityBinding] Concurrent object-id pin for {Upn} — re-reading stored binding", upn);
+                return await GetIdentityBindingAsync(upn);
+            }
+        }
+
+        public async Task<bool> RemoveIdentityBindingAsync(string upn)
+        {
+            await DeleteIfPresentAsync(_identityBindingsTableClient, AdminIdentityBindingEntity.Partition, upn.ToLowerInvariant());
+            return true;
+        }
+
+        private static AdminIdentityBinding MapToBinding(AdminIdentityBindingEntity entity)
+        {
+            return new AdminIdentityBinding
+            {
+                Upn = entity.Upn,
+                TenantId = entity.TenantId,
+                ObjectId = entity.ObjectId ?? string.Empty,
+                BoundBy = entity.BoundBy,
+                BoundAt = entity.BoundDate,
+                ObjectIdPinnedAt = entity.ObjectIdPinnedDate
+            };
+        }
+
         // --- Tenant Members ---
 
         public async Task<List<TenantMember>> GetTenantMembersAsync(string tenantId)

src/Backend/AutopilotMonitor.Functions/DataAccess/TableStorage/TableConfigRepository.cs

@@ -562,6 +562,28 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
             }
         }
 
+        public async Task<Dictionary<string, string>> GetAllNotificationEmailsAsync()
+        {
+            try
+            {
+                var emails = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+
+                await foreach (var entity in _previewWhitelistTableClient.QueryAsync<PreviewNotificationEntity>(
+                    filter: "RowKey eq 'notification-email'"))
+                {
+                    if (!string.IsNullOrWhiteSpace(entity.Email))
+                        emails[entity.PartitionKey.ToLowerInvariant()] = entity.Email;
+                }
+
+                return emails;
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error loading notification emails");
+                throw;
+            }
+        }
+
         public async Task SaveNotificationEmailAsync(string tenantId, string? email)
         {
             if (string.IsNullOrWhiteSpace(email))
@@ -878,6 +900,8 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
                 { "SessionDeletionKillSwitch", config.SessionDeletionKillSwitch },
                 { "VulnerabilityDataLastSyncUtc", config.VulnerabilityDataLastSyncUtc },
                 { "MsrcLastSyncUtc", config.MsrcLastSyncUtc },
+                { "NvdCacheLastRefreshUtc", config.NvdCacheLastRefreshUtc },
+                { "EpssLastSyncUtc", config.EpssLastSyncUtc },
                 { "MaxDiagnosticsDownloadSizeMB", config.MaxDiagnosticsDownloadSizeMB },
                 { "DiagnosticsDownloadTimeoutSeconds", config.DiagnosticsDownloadTimeoutSeconds },
                 { "OpsEventRetentionDays", config.OpsEventRetentionDays },
@@ -947,6 +971,8 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
                 SessionDeletionKillSwitch = entity.GetBoolean("SessionDeletionKillSwitch") ?? false,
                 VulnerabilityDataLastSyncUtc = entity.GetString("VulnerabilityDataLastSyncUtc"),
                 MsrcLastSyncUtc = entity.GetString("MsrcLastSyncUtc"),
+                NvdCacheLastRefreshUtc = entity.GetString("NvdCacheLastRefreshUtc"),
+                EpssLastSyncUtc = entity.GetString("EpssLastSyncUtc"),
                 MaxDiagnosticsDownloadSizeMB = entity.GetInt32("MaxDiagnosticsDownloadSizeMB") ?? 500,
                 DiagnosticsDownloadTimeoutSeconds = entity.GetInt32("DiagnosticsDownloadTimeoutSeconds") ?? 120,
                 OpsEventRetentionDays = entity.GetInt32("OpsEventRetentionDays") ?? 90,

src/Backend/AutopilotMonitor.Functions/DataAccess/TableStorage/TableMetricsRepository.cs

@@ -86,6 +86,9 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
         public Task<int> DeleteUserActivityOlderThanAsync(DateTime cutoffUtc)
             => _storage.DeleteUserActivityOlderThanAsync(cutoffUtc);
 
+        public Task<List<UserSignInIdentity>> GetSignInIdentitiesByUpnAsync(string upn)
+            => _storage.GetSignInIdentitiesByUpnAsync(upn);
+
         public Task RecordUserPresenceAsync(string tenantId, string upn, string userRole)
             => _storage.RecordUserPresenceAsync(tenantId, upn, userRole);
 

src/Backend/AutopilotMonitor.Functions/DataAccess/TableStorage/TableSessionRepository.cs

@@ -22,9 +22,9 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
             _publisher = publisher;
         }
 
-        public async Task<bool> StoreSessionAsync(SessionRegistration registration)
+        public async Task<bool> StoreSessionAsync(SessionRegistration registration, SessionOwner? ownerToStamp = null)
         {
-            var result = await _storage.StoreSessionAsync(registration);
+            var result = await _storage.StoreSessionAsync(registration, ownerToStamp);
             if (result)
                 await _publisher.PublishAsync("session.created", registration, registration.TenantId);
             return result;
@@ -137,6 +137,9 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
         public Task<Dictionary<string, int>> GetImeOffsetOriginHistogramAsync(string tenantId, string sessionId, int maxRows = 500)
             => _storage.GetImeOffsetOriginHistogramAsync(tenantId, sessionId, maxRows);
 
+        public Task UpdateSessionOwnerAsync(string tenantId, string sessionId, SessionOwner owner)
+            => _storage.UpdateSessionOwnerAsync(tenantId, sessionId, owner);
+
         public Task UpdateSessionDiagnosticsBlobAsync(
             string tenantId, string sessionId, string blobName, string? destination = null)
             => _storage.UpdateSessionDiagnosticsBlobAsync(tenantId, sessionId, blobName, destination);
@@ -169,7 +172,7 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
         public Task MarkExcessiveEventsAutoActionedAsync(string tenantId, string sessionId)
             => _storage.MarkExcessiveEventsAutoActionedAsync(tenantId, sessionId);
 
-        public Task<bool> RecordImeVersionAsync(string version, string tenantId, string sessionId)
+        public Task<ImeVersionSighting> RecordImeVersionAsync(string version, string tenantId, string sessionId)
             => _storage.RecordImeVersionAsync(version, tenantId, sessionId);
 
         public Task<List<ImeVersionHistoryEntry>> GetImeVersionHistoryAsync()

src/Backend/AutopilotMonitor.Functions/Extensions/ClaimsPrincipalExtensions.cs

@@ -43,7 +43,12 @@ public static class ClaimsPrincipalExtensions
     /// <summary>
     /// Gets the user's UPN (User Principal Name) from token claims
     /// Falls back to preferred_username if upn is not available
-    /// Supports both v1.0 and v2.0 token formats
+    /// Supports both v1.0 and v2.0 token formats.
+    /// <para>
+    /// Display / audit / row-key use only. Both claims are mutable and reusable across tenants, so no
+    /// cross-tenant authorization is keyed on this value alone — role resolution takes the full
+    /// <see cref="Security.AdminIdentity"/> (upn + tid + oid) and verifies it against the identity binding.
+    /// </para>
     /// </summary>
     public static string? GetUserPrincipalName(this ClaimsPrincipal principal)
     {
@@ -55,8 +60,10 @@ public static class ClaimsPrincipalExtensions
     /// <summary>
     /// Stable per-caller identity for THROTTLING keys — never for authorization or audit.
     /// <para>
-    /// Prefers the UPN so a human caller keeps the same bucket as before. Falls back to the token
-    /// subject (<c>oid</c> → <c>sub</c> → <c>appid</c>/<c>azp</c>) because a valid token need not carry
+    /// Prefers the object id (<c>oid</c>): it is unique per Entra account, so two accounts in different
+    /// tenants that happen to share a UPN string (the API accepts tokens from any tenant) get separate
+    /// buckets instead of throttling each other. Falls back to the UPN, then to the remaining token
+    /// subject claims (<c>sub</c> → <c>appid</c>/<c>azp</c>) because a valid token need not carry
     /// a user identity at all: AuthenticationMiddleware validates issuer/audience/lifetime/signature
     /// but requires no <c>upn</c>, so an app-only (client-credentials) token authenticates fine and
     /// reaches every AuthenticatedUser route. Without this fallback such a caller would present an
@@ -71,9 +78,8 @@ public static class ClaimsPrincipalExtensions
     /// </summary>
     public static string? GetCallerId(this ClaimsPrincipal principal)
     {
-        return principal.GetUserPrincipalName()
-               ?? principal.FindFirst("oid")?.Value
-               ?? principal.FindFirst("http://schemas.microsoft.com/identity/claims/objectidentifier")?.Value
+        return principal.GetObjectId()
+               ?? principal.GetUserPrincipalName()
                ?? principal.FindFirst("sub")?.Value
                ?? principal.FindFirst(ClaimTypes.NameIdentifier)?.Value
                ?? principal.FindFirst("appid")?.Value

src/Backend/AutopilotMonitor.Functions/Functions/Admin/DelegatedAdminManagementFunction.cs

@@ -24,17 +24,20 @@ public class DelegatedAdminManagementFunction
 {
     private readonly ILogger<DelegatedAdminManagementFunction> _logger;
     private readonly DelegatedAdminService _delegatedAdminService;
+    private readonly AdminIdentityResolver _identityResolver;
     private readonly IMaintenanceRepository _maintenanceRepo;
     private readonly ISignalRNotificationService _signalRService;
 
     public DelegatedAdminManagementFunction(
         ILogger<DelegatedAdminManagementFunction> logger,
         DelegatedAdminService delegatedAdminService,
+        AdminIdentityResolver identityResolver,
         IMaintenanceRepository maintenanceRepo,
         ISignalRNotificationService signalRService)
     {
         _logger = logger;
         _delegatedAdminService = delegatedAdminService;
+        _identityResolver = identityResolver;
         _maintenanceRepo = maintenanceRepo;
         _signalRService = signalRService;
     }
@@ -68,14 +71,28 @@ public class DelegatedAdminManagementFunction
         if (validationError != null)
             return await Bad(req, validationError);
 
-        // Edition note: TARGET tenants may be any edition — an MSP on Pro may manage Community
-        // customers. The Pro requirement applies to the delegated admin's HOME tenant and is
-        // enforced at resolve time (DelegatedAdminService.GetScopeAsync gates on the JWT tid). It cannot
-        // be checked here: at grant time only the UPN is known, and UPN-domain → tenant mapping is not
-        // reliable (multi-domain tenants). Grants to non-Pro-homed admins are simply inert.
-        var entry = await _delegatedAdminService.UpsertAsync(
-            body!.Upn, body.TenantId, role,
-            Constants.DelegatedStatus.Active, Constants.DelegatedSource.OperatorGranted, currentUpn ?? "");
+        // The UPN's identity binding (home tenant + object id) is resolved automatically — sign-in history,
+        // then UPN domain → onboarded tenant; the body may override it. Unresolvable ⇒ 422 and the UI asks
+        // the operator to pick the tenant. Edition note: TARGET tenants may be any edition — an MSP on Pro
+        // may manage Community customers; the Pro requirement applies to the HOME tenant and is enforced at
+        // resolve time (DelegatedAdminService.GetScopeAsync gates on the JWT tid), so grants to non-Pro-homed
+        // admins are simply inert. A binding conflict (UPN already homed elsewhere) is a 409, never a silent rebind.
+        var identity = await IdentityBindingRequest.ResolveForGrantAsync(_identityResolver, body!.Upn, body.HomeTenantId, body.ObjectId);
+        if (identity == null)
+            return await Unresolved(req);
+
+        DelegatedAdminEntry entry;
+        try
+        {
+            entry = await _delegatedAdminService.UpsertAsync(
+                body.Upn, body.TenantId, role,
+                Constants.DelegatedStatus.Active, Constants.DelegatedSource.OperatorGranted, currentUpn ?? "",
+                identity.Value.TenantId, identity.Value.ObjectId);
+        }
+        catch (IdentityBindingConflictException ex)
+        {
+            return await Conflict(req, ex.Message);
+        }
 
         await _maintenanceRepo.LogAuditEntryAsync(
             entry.TenantId, "CREATE", "DelegatedAdmin", entry.Upn, currentUpn ?? "",
@@ -84,6 +101,7 @@ public class DelegatedAdminManagementFunction
                 { "Role", entry.Role },
                 { "Status", entry.Status },
                 { "Source", entry.Source },
+                { "HomeTenantId", identity.Value.TenantId.ToLowerInvariant() },
             });
 
         _logger.LogInformation("Delegated grant: {Upn} -> {TenantId} ({Role}) by {By}",
@@ -211,6 +229,10 @@ public class DelegatedAdminManagementFunction
         if (!Guid.TryParse(body.TenantId, out _))
             return "a valid tenantId (GUID) is required";
 
+        var bindingError = IdentityBindingRequest.ValidateOptional(body.HomeTenantId, body.ObjectId);
+        if (bindingError != null)
+            return bindingError;
+
         role = string.IsNullOrWhiteSpace(body.Role) ? Constants.DelegatedRoles.DelegatedReader : body.Role!;
         if (role != Constants.DelegatedRoles.DelegatedReader && role != Constants.DelegatedRoles.DelegatedAdmin)
             return $"role must be '{Constants.DelegatedRoles.DelegatedReader}' or '{Constants.DelegatedRoles.DelegatedAdmin}'";
@@ -224,11 +246,30 @@ public class DelegatedAdminManagementFunction
         await bad.WriteAsJsonAsync(new { error });
         return bad;
     }
+
+    private static async Task<HttpResponseData> Conflict(HttpRequestData req, string error)
+    {
+        var conflict = req.CreateResponse(HttpStatusCode.Conflict);
+        await conflict.WriteAsJsonAsync(new { error });
+        return conflict;
+    }
+
+    private static async Task<HttpResponseData> Unresolved(HttpRequestData req)
+    {
+        var unresolved = req.CreateResponse(HttpStatusCode.UnprocessableEntity);
+        await unresolved.WriteAsJsonAsync(new { error = IdentityBindingRequest.HomeTenantUnresolvedMessage, code = IdentityBindingRequest.HomeTenantUnresolvedCode });
+        return unresolved;
+    }
 }
 
 public class GrantDelegatedAdminRequest
 {
     public string Upn { get; set; } = string.Empty;
+    /// <summary>The MANAGED (target) tenant the UPN may read.</summary>
     public string TenantId { get; set; } = string.Empty;
     public string? Role { get; set; }
+    /// <summary>The grantee's HOME Entra tenant id (optional override) — resolved from sign-in history / UPN domain when omitted.</summary>
+    public string? HomeTenantId { get; set; }
+    /// <summary>The grantee's Entra object id (optional) — taken from sign-in history, else pinned on their first sign-in.</summary>
+    public string? ObjectId { get; set; }
 }

src/Backend/AutopilotMonitor.Functions/Functions/Admin/IdentityBindingManagementFunction.cs

@@ -0,0 +1,190 @@
+using System.Net;
+using AutopilotMonitor.Functions.Helpers;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.DataAccess;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.Azure.Functions.Worker;
+using Microsoft.Azure.Functions.Worker.Http;
+using Microsoft.Extensions.Logging;
+
+namespace AutopilotMonitor.Functions.Functions.Admin;
+
+/// <summary>
+/// GlobalAdmin management of <b>admin identity bindings</b> — the immutable Entra identity (home tenant id +
+/// object id) behind every UPN that holds a cross-tenant role (GlobalAdmins, DelegatedAdmins, TenantGroupAssignments).
+/// Grants create a binding implicitly and REFUSE to overwrite one (409); this surface is the explicit, audited
+/// path for the two legitimate changes: re-homing a UPN in another tenant, and re-pinning the object id after
+/// the UPN was re-assigned to a new account (PUT without objectId clears the pin so the next sign-in from the
+/// bound tenant re-pins). DELETE makes every role row of the UPN inert without touching the rows.
+///
+/// Reads are GlobalReadOrAdmin; mutations are GlobalAdminOnly (route catalog). Audited under the binding's
+/// HOME tenant with entity <c>AdminIdentityBinding</c>.
+/// </summary>
+public class IdentityBindingManagementFunction
+{
+    private readonly ILogger<IdentityBindingManagementFunction> _logger;
+    private readonly AdminIdentityBindingService _bindings;
+    private readonly IMaintenanceRepository _maintenanceRepo;
+
+    private const string AuditEntity = "AdminIdentityBinding";
+
+    public IdentityBindingManagementFunction(
+        ILogger<IdentityBindingManagementFunction> logger,
+        AdminIdentityBindingService bindings,
+        IMaintenanceRepository maintenanceRepo)
+    {
+        _logger = logger;
+        _bindings = bindings;
+        _maintenanceRepo = maintenanceRepo;
+    }
+
+    /// <summary>GET /api/global/identity-bindings — every binding. GlobalReadOrAdmin.</summary>
+    [Function("GetIdentityBindings")]
+    [Authorize]
+    public async Task<HttpResponseData> GetIdentityBindings(
+        [HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "global/identity-bindings")] HttpRequestData req)
+    {
+        var bindings = await _bindings.GetAllAsync();
+        var response = req.CreateResponse(HttpStatusCode.OK);
+        await response.WriteAsJsonAsync(new { bindings });
+        return response;
+    }
+
+    /// <summary>
+    /// PUT /api/global/identity-bindings/{upn} — create or REPLACE the binding. GlobalAdminOnly.
+    /// Body: { "homeTenantId": "&lt;GUID&gt;", "objectId": "&lt;GUID, optional&gt;" }. Omitting objectId clears
+    /// any pinned object id (re-pinned on the next sign-in from the home tenant).
+    /// </summary>
+    [Function("PutIdentityBinding")]
+    [Authorize]
+    public async Task<HttpResponseData> PutIdentityBinding(
+        [HttpTrigger(AuthorizationLevel.Anonymous, "put", Route = "global/identity-bindings/{upn}")] HttpRequestData req,
+        string upn, FunctionContext context)
+    {
+        var currentUpn = context.GetRequestContext().UserPrincipalName;
+        upn = upn.ToLowerInvariant();
+
+        var body = await req.ReadFromJsonAsync<IdentityBindingRequest>();
+        var error = IdentityBindingRequest.Validate(body?.HomeTenantId, body?.ObjectId);
+        if (error != null)
+            return await Bad(req, error);
+
+        var previous = await _bindings.GetAsync(upn);
+        var binding = await _bindings.RebindAsync(upn, body!.HomeTenantId!, body.ObjectId, currentUpn ?? "");
+
+        var details = new Dictionary<string, string>
+        {
+            { "HomeTenantId", binding.TenantId },
+            { "ObjectId", binding.IsObjectIdPinned ? binding.ObjectId : "(unpinned)" },
+        };
+        if (previous != null)
+        {
+            details["PreviousHomeTenantId"] = previous.TenantId;
+            details["PreviousObjectId"] = previous.IsObjectIdPinned ? previous.ObjectId : "(unpinned)";
+        }
+        await _maintenanceRepo.LogAuditEntryAsync(
+            binding.TenantId, previous == null ? "CREATE" : "UPDATE", AuditEntity, upn, currentUpn ?? "", details);
+        // Warning on purpose: every rebind is a security-relevant, operator-initiated identity change.
+        _logger.LogWarning("[IdentityBinding] {Action} binding for {Upn}: tenant {TenantId}, objectId {ObjectId} by {By}",
+            previous == null ? "Created" : "Replaced", upn, binding.TenantId,
+            binding.IsObjectIdPinned ? binding.ObjectId : "(unpinned)", currentUpn);
+
+        var response = req.CreateResponse(HttpStatusCode.OK);
+        await response.WriteAsJsonAsync(new { binding });
+        return response;
+    }
+
+    /// <summary>DELETE /api/global/identity-bindings/{upn} — remove the binding (all role rows of the UPN become inert). GlobalAdminOnly.</summary>
+    [Function("DeleteIdentityBinding")]
+    [Authorize]
+    public async Task<HttpResponseData> DeleteIdentityBinding(
+        [HttpTrigger(AuthorizationLevel.Anonymous, "delete", Route = "global/identity-bindings/{upn}")] HttpRequestData req,
+        string upn, FunctionContext context)
+    {
+        var currentUpn = context.GetRequestContext().UserPrincipalName;
+        upn = upn.ToLowerInvariant();
+
+        // Self-removal would lock the acting GA out of every GlobalAdminOnly route, including this one.
+        if (string.Equals(upn, currentUpn, StringComparison.OrdinalIgnoreCase))
+            return await Bad(req, "You cannot remove your own identity binding");
+
+        var previous = await _bindings.GetAsync(upn);
+        if (previous == null)
+        {
+            var notFound = req.CreateResponse(HttpStatusCode.NotFound);
+            await notFound.WriteAsJsonAsync(new { error = "Binding not found" });
+            return notFound;
+        }
+
+        await _bindings.RemoveAsync(upn);
+        await _maintenanceRepo.LogAuditEntryAsync(
+            previous.TenantId, "DELETE", AuditEntity, upn, currentUpn ?? "",
+            new Dictionary<string, string>
+            {
+                { "HomeTenantId", previous.TenantId },
+                { "ObjectId", previous.IsObjectIdPinned ? previous.ObjectId : "(unpinned)" },
+            });
+        _logger.LogWarning("[IdentityBinding] Removed binding for {Upn} (was tenant {TenantId}) by {By}",
+            upn, previous.TenantId, currentUpn);
+
+        var response = req.CreateResponse(HttpStatusCode.OK);
+        await response.WriteAsJsonAsync(new { message = "Binding removed" });
+        return response;
+    }
+
+    private static async Task<HttpResponseData> Bad(HttpRequestData req, string error)
+    {
+        var bad = req.CreateResponse(HttpStatusCode.BadRequest);
+        await bad.WriteAsJsonAsync(new { error });
+        return bad;
+    }
+}
+
+/// <summary>Body of PUT global/identity-bindings/{upn}; also the shared validator for the binding fields every grant carries.</summary>
+public class IdentityBindingRequest
+{
+    /// <summary>
+    /// The identity a grant binds: the operator-supplied values when present, otherwise the resolver's answer.
+    /// Returns null when neither yields a home tenant — the endpoint answers 422 <see cref="HomeTenantUnresolvedCode"/>
+    /// and the UI offers a tenant picker. A supplied object id always wins over a resolved one.
+    /// </summary>
+    public static async Task<(string TenantId, string? ObjectId)?> ResolveForGrantAsync(
+        AdminIdentityResolver resolver, string upn, string? homeTenantId, string? objectId)
+    {
+        objectId = string.IsNullOrWhiteSpace(objectId) ? null : objectId;
+        if (!string.IsNullOrWhiteSpace(homeTenantId))
+            return (homeTenantId, objectId);
+
+        var resolved = await resolver.ResolveAsync(upn);
+        return resolved == null ? null : (resolved.TenantId, objectId ?? resolved.ObjectId);
+    }
+
+    public string? HomeTenantId { get; set; }
+    public string? ObjectId { get; set; }
+
+    /// <summary>Returns the 400 message, or null when the fields are valid (home tenant = GUID required; object id = GUID or absent).</summary>
+    public static string? Validate(string? homeTenantId, string? objectId)
+    {
+        if (string.IsNullOrWhiteSpace(homeTenantId))
+            return "a valid homeTenantId (GUID — the Entra tenant the person signs in from) is required";
+        return ValidateOptional(homeTenantId, objectId);
+    }
+
+    /// <summary>
+    /// Grant-time variant: the home tenant MAY be absent (the backend resolves it from sign-in history or the
+    /// UPN domain — see <see cref="AdminIdentityResolver"/>); when supplied it must be a GUID, as must the object id.
+    /// </summary>
+    public static string? ValidateOptional(string? homeTenantId, string? objectId)
+    {
+        if (!string.IsNullOrWhiteSpace(homeTenantId) && !Guid.TryParse(homeTenantId, out _))
+            return "homeTenantId must be a GUID (the Entra tenant the person signs in from) when supplied";
+        if (!string.IsNullOrWhiteSpace(objectId) && !Guid.TryParse(objectId, out _))
+            return "objectId must be a GUID (the person's Entra object id) when supplied";
+        return null;
+    }
+
+    /// <summary>Error code the grant endpoints return (HTTP 422) when the home tenant could not be resolved automatically.</summary>
+    public const string HomeTenantUnresolvedCode = "HomeTenantUnresolved";
+    public const string HomeTenantUnresolvedMessage =
+        "The person's home tenant could not be resolved automatically (no previous sign-in, and the UPN domain does not belong to an onboarded tenant). Select the tenant they sign in from.";
+}

src/Backend/AutopilotMonitor.Functions/Functions/Admin/TenantGroupManagementFunction.cs

@@ -29,6 +29,7 @@ public class TenantGroupManagementFunction
 {
     private readonly ILogger<TenantGroupManagementFunction> _logger;
     private readonly DelegatedAdminService _delegatedAdminService;
+    private readonly AdminIdentityResolver _identityResolver;
     private readonly IMaintenanceRepository _maintenanceRepo;
     private readonly ISignalRNotificationService _signalRService;
 
@@ -37,11 +38,13 @@ public class TenantGroupManagementFunction
     public TenantGroupManagementFunction(
         ILogger<TenantGroupManagementFunction> logger,
         DelegatedAdminService delegatedAdminService,
+        AdminIdentityResolver identityResolver,
         IMaintenanceRepository maintenanceRepo,
         ISignalRNotificationService signalRService)
     {
         _logger = logger;
         _delegatedAdminService = delegatedAdminService;
+        _identityResolver = identityResolver;
         _maintenanceRepo = maintenanceRepo;
         _signalRService = signalRService;
     }
@@ -223,7 +226,11 @@ public class TenantGroupManagementFunction
 
     /// <summary>
     /// POST /api/global/tenant-groups/{groupId}/assignees — assign a UPN to the group. GlobalAdminOnly.
-    /// Body: { "upn": "user@domain.com", "role": "DelegatedReader" | "DelegatedAdmin" }.
+    /// Body: { "upn": "user@domain.com", "role": "DelegatedReader" | "DelegatedAdmin",
+    ///         "homeTenantId": "&lt;optional override&gt;", "objectId": "&lt;optional&gt;" }.
+    /// The UPN's identity binding is resolved automatically (sign-in history, then UPN domain → onboarded
+    /// tenant); 422 HomeTenantUnresolved when neither works, 409 if the UPN is already bound elsewhere
+    /// (rebind explicitly via global/identity-bindings).
     /// </summary>
     [Function("AssignTenantGroup")]
     [Authorize]
@@ -242,14 +249,37 @@ public class TenantGroupManagementFunction
         if (role != Constants.DelegatedRoles.DelegatedReader && role != Constants.DelegatedRoles.DelegatedAdmin)
             return await Bad(req, $"role must be '{Constants.DelegatedRoles.DelegatedReader}' or '{Constants.DelegatedRoles.DelegatedAdmin}'");
 
+        var bindingError = IdentityBindingRequest.ValidateOptional(body.HomeTenantId, body.ObjectId);
+        if (bindingError != null)
+            return await Bad(req, bindingError);
+
         // Guard against assigning to a non-existent group (would create an orphan assignment row).
         var group = await _delegatedAdminService.GetGroupAsync(groupId);
         if (group == null)
             return await NotFound(req);
 
         var upn = body.Upn.ToLowerInvariant();
+        var identity = await IdentityBindingRequest.ResolveForGrantAsync(_identityResolver, upn, body.HomeTenantId, body.ObjectId);
+        if (identity == null)
+        {
+            var unresolved = req.CreateResponse(HttpStatusCode.UnprocessableEntity);
+            await unresolved.WriteAsJsonAsync(new { error = IdentityBindingRequest.HomeTenantUnresolvedMessage, code = IdentityBindingRequest.HomeTenantUnresolvedCode });
+            return unresolved;
+        }
+
         // The service re-checks existence (covers a delete racing this assign) — skip the audit if it no-ops.
-        var assigned = await _delegatedAdminService.AssignGroupAsync(upn, groupId, role, true, currentUpn ?? "");
+        bool assigned;
+        try
+        {
+            assigned = await _delegatedAdminService.AssignGroupAsync(
+                upn, groupId, role, true, currentUpn ?? "", identity.Value.TenantId, identity.Value.ObjectId);
+        }
+        catch (IdentityBindingConflictException ex)
+        {
+            var conflict = req.CreateResponse(HttpStatusCode.Conflict);
+            await conflict.WriteAsJsonAsync(new { error = ex.Message });
+            return conflict;
+        }
         if (!assigned)
             return await NotFound(req);
 
@@ -365,4 +395,8 @@ public class AssignGroupRequest
 {
     public string Upn { get; set; } = string.Empty;
     public string? Role { get; set; }
+    /// <summary>The assignee's HOME Entra tenant id (optional override) — resolved from sign-in history / UPN domain when omitted.</summary>
+    public string? HomeTenantId { get; set; }
+    /// <summary>The assignee's Entra object id (optional) — taken from sign-in history, else pinned on their first sign-in.</summary>
+    public string? ObjectId { get; set; }
 }

src/Backend/AutopilotMonitor.Functions/Functions/Bootstrap/BootstrapGetAgentConfigFunction.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Net;
 using AutopilotMonitor.Functions.Functions.Config;
 using AutopilotMonitor.Functions.Security;
@@ -53,8 +53,10 @@ namespace AutopilotMonitor.Functions.Functions.Bootstrap
         {
             try
             {
-                // Bootstrap-only: reject requests without X-Bootstrap-Token
-                if (!req.Headers.Contains("X-Bootstrap-Token"))
+                // Bootstrap-only: reject requests without a (non-empty) X-Bootstrap-Token before any
+                // parsing. SecurityValidator enforces the same rule fail-closed for every
+                // /api/bootstrap/* route; this is only the cheap early exit.
+                if (SecurityValidator.GetBootstrapToken(req) == null)
                 {
                     var noToken = req.CreateResponse(HttpStatusCode.Unauthorized);
                     await noToken.WriteAsJsonAsync(new { error = "X-Bootstrap-Token header is required" });

src/Backend/AutopilotMonitor.Functions/Functions/Bootstrap/BootstrapRegisterSessionFunction.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Net;
 using AutopilotMonitor.Functions.Functions.Sessions;
 using AutopilotMonitor.Functions.Security;
@@ -56,8 +56,10 @@ namespace AutopilotMonitor.Functions.Functions.Bootstrap
         {
             try
             {
-                // Bootstrap-only: reject requests without X-Bootstrap-Token
-                if (!req.Headers.Contains("X-Bootstrap-Token"))
+                // Bootstrap-only: reject requests without a (non-empty) X-Bootstrap-Token before any
+                // parsing. SecurityValidator enforces the same rule fail-closed for every
+                // /api/bootstrap/* route; this is only the cheap early exit.
+                if (SecurityValidator.GetBootstrapToken(req) == null)
                 {
                     var noToken = req.CreateResponse(HttpStatusCode.Unauthorized);
                     await noToken.WriteAsJsonAsync(new { success = false, message = "X-Bootstrap-Token header is required" });

src/Backend/AutopilotMonitor.Functions/Functions/Bootstrap/BootstrapReportAgentErrorFunction.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Net;
 using AutopilotMonitor.Functions.Functions.Ingest;
 using AutopilotMonitor.Functions.Security;
@@ -53,8 +53,10 @@ namespace AutopilotMonitor.Functions.Functions.Bootstrap
         {
             try
             {
-                // Bootstrap-only: reject requests without X-Bootstrap-Token
-                if (!req.Headers.Contains("X-Bootstrap-Token"))
+                // Bootstrap-only: reject requests without a (non-empty) X-Bootstrap-Token before any
+                // parsing. SecurityValidator enforces the same rule fail-closed for every
+                // /api/bootstrap/* route; this is only the cheap early exit.
+                if (SecurityValidator.GetBootstrapToken(req) == null)
                 {
                     var noToken = req.CreateResponse(HttpStatusCode.Unauthorized);
                     await noToken.WriteAsJsonAsync(new { error = "X-Bootstrap-Token header is required" });
@@ -77,7 +79,7 @@ namespace AutopilotMonitor.Functions.Functions.Bootstrap
                     return req.CreateResponse(HttpStatusCode.NotFound);
                 }
 
-                var (_, errorResponse) = await req.ValidateSecurityAsync(
+                var (validation, errorResponse) = await req.ValidateSecurityAsync(
                     tenantId, _configService, _adminConfigService, _rateLimitService,
                     _autopilotDeviceValidator, _corporateIdentifierValidator,
                     _logger, bootstrapSessionService: _bootstrapSessionService,
@@ -88,7 +90,7 @@ namespace AutopilotMonitor.Functions.Functions.Bootstrap
                     return errorResponse;
                 }
 
-                return await _inner.ProcessReportErrorAsync(req, tenantId);
+                return await _inner.ProcessReportErrorAsync(req, tenantId, validation);
             }
             catch (Exception ex)
             {

src/Backend/AutopilotMonitor.Functions/Functions/Config/GetTenantFeatureFlagsFunction.cs

@@ -86,10 +86,7 @@ namespace AutopilotMonitor.Functions.Functions.Config
                 // succeed right now (mode not Off + a usable destination). Members below Admin cannot
                 // read the full config, so this boolean is their only signal. Deliberately exposes no
                 // destination detail — just "would an upload work".
-                diagnosticsUploadConfigured =
-                    !string.Equals(config.DiagnosticsUploadMode ?? "Off", "Off", StringComparison.OrdinalIgnoreCase)
-                    && GetAgentConfigFunction.ResolveDiagnosticsUploadEnabled(
-                        config.DiagnosticsBlobSasUrl, config.DiagnosticsUploadDestination),
+                diagnosticsUploadConfigured = DiagnosticsUploadConfigChange.IsConfigured(config),
                 // Drives the "Autopilot Device Validation disabled" dashboard banner
                 // (useTenantSecurityConfig).
                 validateAutopilotDevice = config.ValidateAutopilotDevice,

src/Backend/AutopilotMonitor.Functions/Functions/Config/UpdateTenantConfigurationFunction.cs

@@ -21,17 +21,32 @@ namespace AutopilotMonitor.Functions.Functions.Config
         private readonly ILogger<UpdateTenantConfigurationFunction> _logger;
         private readonly TenantConfigurationService _configService;
         private readonly IMaintenanceRepository _maintenanceRepo;
+        private readonly OpsEventService _opsEventService;
 
         public UpdateTenantConfigurationFunction(
             ILogger<UpdateTenantConfigurationFunction> logger,
             TenantConfigurationService configService,
-            IMaintenanceRepository maintenanceRepo)
+            IMaintenanceRepository maintenanceRepo,
+            OpsEventService opsEventService)
         {
             _logger = logger;
             _configService = configService;
             _maintenanceRepo = maintenanceRepo;
+            _opsEventService = opsEventService;
         }
 
+        /// <summary>
+        /// Write-path label for the session-detail Collect Logs quick-config dialog. The dialog
+        /// sends <c>?intent=collect-logs</c> so the backup snapshot and the ops event can name
+        /// the path — a plain Settings/Admin PUT is <c>portal-put</c>. Allow-listed, never echoed
+        /// from arbitrary input.
+        /// </summary>
+        internal const string CollectLogsIntent = "collect-logs";
+        internal const string CollectLogsSource = "portal-collect-logs";
+
+        internal static string ResolveWriteSource(string? intent) =>
+            string.Equals(intent, CollectLogsIntent, StringComparison.OrdinalIgnoreCase) ? CollectLogsSource : "portal-put";
+
         [Function("UpdateTenantConfiguration")]
         public async Task<HttpResponseData> Run(
             [HttpTrigger(AuthorizationLevel.Anonymous, "put", "post", Route = "config/{tenantId}")] HttpRequestData req,
@@ -122,8 +137,7 @@ namespace AutopilotMonitor.Functions.Functions.Config
                         config.EnableEspContinueAnywayObservation != existingConfig.EnableEspContinueAnywayObservation ||
                         config.CustomRateLimitRequestsPerMinute != existingConfig.CustomRateLimitRequestsPerMinute ||
                         config.CustomUserRateLimitRequestsPerMinute != existingConfig.CustomUserRateLimitRequestsPerMinute ||
-                        config.Disabled != existingConfig.Disabled ||
-                        config.ValidateDeviceAssociation != existingConfig.ValidateDeviceAssociation)
+                        config.Disabled != existingConfig.Disabled)
                     {
                         _logger.LogWarning(
                             "Tenant Admin {User} attempted to modify GA-only fields for tenant {TenantId}",
@@ -142,12 +156,6 @@ namespace AutopilotMonitor.Functions.Functions.Config
                     config.Disabled = existingConfig.Disabled;
                     config.DisabledReason = existingConfig.DisabledReason;
                     config.DisabledUntil = existingConfig.DisabledUntil;
-                    // DevPrep "Device association" toggle is GA-only during Private Preview.
-                    // TODO(devprep-followup): missing xUnit test for this GA-gate — needs
-                    // UpdateTenantConfigurationFunction test harness (mock HttpRequestData +
-                    // RequestContext + TenantConfigurationService). Tracked in
-                    // memory/project_devprep_followups.md.
-                    config.ValidateDeviceAssociation = existingConfig.ValidateDeviceAssociation;
                 }
 
                 // App-reg homing is IMMUTABLE via the generic PUT — for ALL callers, GA included.
@@ -190,7 +198,8 @@ namespace AutopilotMonitor.Functions.Functions.Config
                 config.TrialGrantedBy = existingConfig.TrialGrantedBy;
 
                 // Save configuration (retention cap already enforced by ValidateModel above)
-                await _configService.SaveConfigurationAsync(config, "portal-put", null);
+                var writeSource = ResolveWriteSource(req.Query["intent"]);
+                await _configService.SaveConfigurationAsync(config, writeSource, null);
 
                 var changes = ConfigDiffHelper.GetChanges(existingConfig, config);
                 await _maintenanceRepo.LogAuditEntryAsync(
@@ -202,6 +211,15 @@ namespace AutopilotMonitor.Functions.Functions.Config
                     changes.Count > 0 ? changes : null
                 );
 
+                // Operator visibility for the Collect Logs capability flip (the quick-config
+                // dialog writes through this PUT). OpsEventService never throws.
+                var diagChange = DiagnosticsUploadConfigChange.Detect(existingConfig, config);
+                if (diagChange != null)
+                {
+                    await _opsEventService.RecordDiagnosticsUploadConfigChangedAsync(
+                        requestCtx.TargetTenantId, config.DomainName, diagChange, userIdentifier ?? "unknown", writeSource);
+                }
+
                 var response = req.CreateResponse(HttpStatusCode.OK);
                 await response.WriteAsJsonAsync(new
                 {

src/Backend/AutopilotMonitor.Functions/Functions/Infrastructure/AuthFunction.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.Net;
 using AutopilotMonitor.Functions.Extensions;
+using AutopilotMonitor.Functions.Functions.Admin;
 using AutopilotMonitor.Functions.Security;
 using AutopilotMonitor.Functions.Services;
 using AutopilotMonitor.Shared;
@@ -31,6 +32,7 @@ public class AuthFunction
     private readonly McpUserService _mcpUserService;
     private readonly Services.Activation.ITenantAutoApproveEnqueuer _tenantAutoApproveEnqueuer;
     private readonly EntraAppRegistry _appRegistry;
+    private readonly AdminIdentityResolver _identityResolver;
 
     public AuthFunction(
         ILogger<AuthFunction> logger,
@@ -44,9 +46,11 @@ public class AuthFunction
         GlobalNotificationService globalNotificationService,
         McpUserService mcpUserService,
         Services.Activation.ITenantAutoApproveEnqueuer tenantAutoApproveEnqueuer,
-        EntraAppRegistry appRegistry)
+        EntraAppRegistry appRegistry,
+        AdminIdentityResolver identityResolver)
     {
         _logger = logger;
+        _identityResolver = identityResolver;
         _globalAdminService = globalAdminService;
         _delegatedAdminService = delegatedAdminService;
         _tenantConfigService = tenantConfigService;
@@ -99,12 +103,14 @@ public class AuthFunction
         // A delegated-only external MSP login must not phantom-onboard its home tenant (see the side-effect
         // gate below). A genuine first-user still gets their config created by HandleNewTenantDomainAsync.
         var tenantConfigTask = _tenantConfigService.TryGetConfigurationAsync(tenantId);
-        var globalRoleTask = _globalAdminService.GetGlobalRoleAsync(upn);
-        // tenantId = JWT tid = the caller's home tenant — gates the delegated (MSP) scope (Pro-only seat).
-        var delegatedScopeTask = _delegatedAdminService.GetScopeAsync(upn, tenantId);
+        // Cross-tenant roles resolve on the FULL identity (upn + tid + oid) against the UPN's identity
+        // binding — never on the UPN alone. Null (no oid in the token) ⇒ no platform/delegated role.
+        var identity = AdminIdentity.FromPrincipal(principal);
+        var globalRoleTask = _globalAdminService.GetGlobalRoleAsync(identity);
+        var delegatedScopeTask = _delegatedAdminService.GetScopeAsync(identity);
         var isApprovedTask = _previewWhitelistService.IsApprovedAsync(tenantId);
         var membershipTask = _tenantAdminsService.GetTableMembershipAsync(tenantId, upn);
-        var mcpCheckTask = _mcpUserService.IsAllowedAsync(upn, tenantId);
+        var mcpCheckTask = _mcpUserService.IsAllowedAsync(upn, tenantId, objectId);
         var existingAdminsTask = _tenantAdminsService.GetTenantAdminsAsync(tenantId);
 
         await Task.WhenAll(tenantConfigTask, globalRoleTask, delegatedScopeTask, isApprovedTask,
@@ -200,7 +206,7 @@ public class AuthFunction
         }
 
         var upn = principal.GetUserPrincipalName();
-        var isAdmin = await _globalAdminService.IsGlobalAdminAsync(upn);
+        var isAdmin = await _globalAdminService.IsGlobalAdminAsync(AdminIdentity.FromPrincipal(principal));
 
         var response = req.CreateResponse(HttpStatusCode.OK);
         await response.WriteAsJsonAsync(new { isGlobalAdmin = isAdmin, upn });
@@ -248,8 +254,34 @@ public class AuthFunction
             await badRequestResponse.WriteAsJsonAsync(new { error = "UPN is required" });
             return badRequestResponse;
         }
+        // The row is inert until the UPN is bound to the identity that may use it. The home tenant is resolved
+        // automatically (sign-in history, then UPN domain → onboarded tenant); the body may override it.
+        var bindingError = IdentityBindingRequest.ValidateOptional(body.HomeTenantId, body.ObjectId);
+        if (bindingError != null)
+        {
+            var badRequestResponse = req.CreateResponse(HttpStatusCode.BadRequest);
+            await badRequestResponse.WriteAsJsonAsync(new { error = bindingError });
+            return badRequestResponse;
+        }
+        var identity = await IdentityBindingRequest.ResolveForGrantAsync(_identityResolver, body.Upn, body.HomeTenantId, body.ObjectId);
+        if (identity == null)
+        {
+            var unresolved = req.CreateResponse(HttpStatusCode.UnprocessableEntity);
+            await unresolved.WriteAsJsonAsync(new { error = IdentityBindingRequest.HomeTenantUnresolvedMessage, code = IdentityBindingRequest.HomeTenantUnresolvedCode });
+            return unresolved;
+        }
 
-        var newAdmin = await _globalAdminService.AddGlobalAdminAsync(body.Upn, currentUpn!);
+        GlobalAdminEntity newAdmin;
+        try
+        {
+            newAdmin = await _globalAdminService.AddGlobalAdminAsync(body.Upn, currentUpn!, identity.Value.TenantId, identity.Value.ObjectId);
+        }
+        catch (IdentityBindingConflictException ex)
+        {
+            var conflict = req.CreateResponse(HttpStatusCode.Conflict);
+            await conflict.WriteAsJsonAsync(new { error = ex.Message });
+            return conflict;
+        }
 
         _logger.LogInformation($"Global Admin added: {body.Upn} by {currentUpn}");
 
@@ -614,4 +646,8 @@ internal class AuthDecisionResult
 public class AddGlobalAdminRequest
 {
     public string Upn { get; set; } = string.Empty;
+    /// <summary>The grantee's home Entra tenant id (optional override) — resolved from sign-in history / UPN domain when omitted.</summary>
+    public string? HomeTenantId { get; set; }
+    /// <summary>The grantee's Entra object id (optional) — taken from sign-in history, else pinned on their first sign-in.</summary>
+    public string? ObjectId { get; set; }
 }

src/Backend/AutopilotMonitor.Functions/Functions/Infrastructure/HealthCheckFunction.cs

@@ -110,7 +110,7 @@ namespace AutopilotMonitor.Functions.Functions.Infrastructure
             // The route is registered as AuthenticatedUser, so PolicyEnforcementMiddleware
             // does NOT compute IsGlobalAdmin; resolve it directly via GlobalAdminService.
             var requestCtx = context.GetRequestContext();
-            var isGlobalAdmin = await _globalAdminService.IsGlobalAdminAsync(requestCtx.UserPrincipalName);
+            var isGlobalAdmin = await _globalAdminService.IsGlobalAdminAsync(AdminIdentity.FromRequestContext(requestCtx));
 
             // Perform comprehensive health checks (endpoint URLs only for Global Admins)
             var healthCheckResult = await _healthCheckService.PerformAllChecksAsync(includeEndpointUrls: isGlobalAdmin);
@@ -154,7 +154,7 @@ namespace AutopilotMonitor.Functions.Functions.Infrastructure
             // Authentication enforced by PolicyEnforcementMiddleware (AuthenticatedUser).
             // The MCP server URL is infrastructure topology — include it only for Global Admins.
             var requestCtx = context.GetRequestContext();
-            var isGlobalAdmin = await _globalAdminService.IsGlobalAdminAsync(requestCtx.UserPrincipalName);
+            var isGlobalAdmin = await _globalAdminService.IsGlobalAdminAsync(AdminIdentity.FromRequestContext(requestCtx));
             var check = await _healthCheckService.CheckMcpServerAsync(includeEndpointUrl: isGlobalAdmin);
 
             var response = req.CreateResponse(HttpStatusCode.OK);