docs: correct portal-prefetch root cause (h2, server-side queue) + measured outcome

The HTTP/1.1 / six-connection-cap claim was wrong — it came from the
Schannel curl build that cannot speak HTTP/2. ALPN (openssl s_client)
and .NET HttpClient confirm the portal negotiates h2; the queue is
server-side in the SWA SSR runtime. Doc, index, log and the
GlobalSidebar comment now describe the real mechanism.

Adds the 2026-07-28 outcome section: Standard plan changed nothing
(stratified p50s match, Mann-Whitney p=0.81); prefetch={false} removed
the freezes (worst totalDuration 225s -> 4.9s) and also removed an
accidental keep-alive (~150ms added to cold navigations).

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

docs/agent/autopilot-ztd-diagnostics.md

@@ -119,6 +119,19 @@ normal IME deployment flow. Spam containment, in order:
    payload; the event's own timestamp is the emission time, so the session's `StartedAt`
    (which the backend aligns to the earliest event) is not dragged backwards.
 
+Presentation (2026-07-28, customer feedback — an unannounced wall of pre-agent Error
+events read like a live failure):
+
+- The scan buffers the (capped) record set, first emits an **Info summary event**
+  (`modern_deployment_log`, payload `backfillSummary: true` + `replayedCount` /
+  `droppedOverCap` / `lookbackMinutes`) announcing the replay block, then replays the
+  records **oldest-first** so the timeline sequence follows event-log chronology.
+- The web timeline (`EventTimeline.tsx`) badges `backfilled: true` events („⟲ Backfilled",
+  slate, explanatory tooltip) and renders the original `timeCreated` as the row time with a
+  "(reported …)" suffix; the expanded metadata block gains a `Recorded` line. Severity is
+  deliberately **not** downgraded — unresolved pre-agent errors must still surface in the
+  Error filter.
+
 # Schema — Error codes (backend known-issue map)
 
 Codes documented in the known-issues / troubleshooting-FAQ pages that appear in ESP/enrollment

docs/agent/gather-rule-debug-log.md

@@ -0,0 +1,108 @@
+---
+type: Concept
+title: Gather Rule Debug Log — the per-tenant evaluation trace for rules that produce nothing
+description: EnableGatherRuleDebugLog (ConfigVersion 36) makes the agent write a local trace file explaining every gather-rule evaluation decision — scope skips, missing intervalSeconds, on_change suppression, empty collector results, logparser position/parse-mode/no-match outcomes — so customers can self-diagnose rules that never show up in the timeline.
+resource: /src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Gather/GatherRuleDebugLog.cs
+tags:
+  - agent
+  - gather-rules
+  - diagnostics
+  - tenant-configuration
+timestamp: 2026-07-28T00:00:00+02:00
+---
+
+# Gather Rule Debug Log
+
+## Schema
+
+### The problem
+
+A gather rule that produces no timeline events is indistinguishable from a rule that
+never ran. The pipeline has many *silent-nothing* exits — before this feature, none of
+them were visible to the customer:
+
+| # | Decision point | Where |
+|---|---|---|
+| 1 | Rule delivered but `Enabled=false` | `GatherRuleExecutor.UpdateRules` |
+| 2 | `trigger=interval` without `intervalSeconds` — never runs | `UpdateRules` timer filter |
+| 3 | Interval timer's first tick comes only after one **full** interval | `UpdateRules` timer creation |
+| 4 | Out of phase scope (`activePhases` / `activeFromPhase` not latched); incl. `currentPhase=Unknown` before the first phase signal | `IsRuleInScopeLocked` |
+| 5 | phase_change / phase_exit dedup — once per (rule, phase) | `OnPhaseChanged` |
+| 6 | Collector returned an **empty** result (e.g. `emitOnlyIfExists=true` and target absent) | `ExecuteRule` |
+| 7 | `emit_mode=on_change` — result hash unchanged, emit suppressed | `ShouldEmitOnChange` |
+| 8 | Guard blocked the target (emits `security_warning`, but the rule yields no data) | `GatherRuleContext.EmitSecurityWarning` |
+| 9 | logparser: no files matched, position tracker says nothing new, regex no-match, plain-text file parsed in default `cmtrace` mode, `maxLines` cap, wildcard capped at 20 files | `LogParserCollector` |
+| 10 | Rule execution threw (agent log had only the message, no stack) | `ExecuteRule` catch |
+
+### The setting
+
+`TenantConfiguration.EnableGatherRuleDebugLog` (`bool?`, default null→false), served to the
+agent as `AgentConfigResponse.EnableGatherRuleDebugLog` — **ConfigVersion 36**. Portal:
+Settings → Agent → Settings, toggle "Gather Rule Debug Log", stored via the usual
+tenant-config roundtrip (`TableConfigRepository` Store+Map). Also shown in the admin
+tenant-config report.
+
+`RemoteConfigMerger` projects the bool onto a runtime path (same pattern as
+`EnableImeMatchLog`): `true` → `Constants.GatherRuleDebugLogPath` =
+`%ProgramData%\AutopilotMonitor\Logs\gather_rules_debug.log`; `false` → null, unless a
+`--gather-debug-log <path>` CLI override supplied a non-default path. The field is not
+security-sensitive and deliberately **survives the offline config cache**.
+
+### The trace file
+
+`GatherRuleDebugLog` is an append-only writer held by `GatherRuleExecutor` and exposed
+to collectors via `GatherRuleContext.DebugLog(ruleId, stage, message)` (null-safe no-op
+when disabled — zero cost on the normal path). Line format:
+
+```
+2026-07-28T09:15:02.123Z | RULE-ID | stage | message
+```
+
+Stages: `config` (registration summary per rule, header, zero-rules note), `trigger`
+(timer scheduled, phase/event fired, dedup), `scope` (skips with reason incl. current
+phase), `exec` (execution start), `collector` (null/empty results with likely cause),
+`guard` (allowlist block), `emit` (event emitted, hash change), `suppress` (on_change
+suppression with hash prefix + streak), `logparser` (per-file outcome: lines read,
+position range, match count, parse failures, regex timeouts, mode; plus the
+`format=text` hint when every line fails CMTrace parsing), `error` (full exception
+**with stack trace** — the agent log keeps only the message).
+
+Volume control: 10 MB cap with a single `.old` rotation generation (~20 MB worst case).
+Every write failure is swallowed — tracing must never break gathering. The trace never
+leaves the device on its own — but because it lives in the agent log folder
+(`Constants.LogDirectory`), the diagnostics package (`DiagnosticsPackageService`,
+`*.log` pattern, `AgentLogs/` section) picks it up automatically, so a customer-initiated
+diagnostics upload hands the trace to support without manual copying.
+
+### Semantics
+
+* **No hot-reload** — the flag is consumed once when `DefaultComponentFactory` builds
+  the `GatherRuleExecutorHost` at session start (per-enrollment lifecycle, same as
+  `EnableImeMatchLog`). Enable it in the tenant, then the *next* enrollment writes the
+  trace.
+* **Zero-rules case is traced too** — flag on + backend delivered no gather rules →
+  a one-shot standalone `config` line, so the file is never just absent.
+* **`--run-gather-rules` always traces** (operator diagnostic mode; CLI override or
+  default path) and mirrors every line to the console under `--console`.
+
+## Examples
+
+A logparser rule with `emit_mode=on_change` that "delivers nothing" becomes:
+
+```
+... | LP-01 | config | registered: trigger=interval, collector=logparser, target=C:\...\app.log, unscoped, emitMode=on_change, interval=300s
+... | LP-01 | trigger | interval timer scheduled every 300s (first run after one full interval — no immediate execution)
+... | LP-01 | exec | executing: collector=logparser, target=C:\...\app.log
+... | LP-01 | logparser | app.log: read 1000 lines from position 0->81234, matched 0, parseFailures=1000, regexTimeouts=0, mode=cmtrace
+... | LP-01 | logparser | every line failed CMTrace parsing — if this is a plain-text log, set parameter format=text
+```
+
+— the answer ("plain-text log parsed in CMTrace mode") is in the file.
+
+## Citations
+
+* Executor + trace points: `../../src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Gather/GatherRuleExecutor.cs`
+* Writer: `../../src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Gather/GatherRuleDebugLog.cs`
+* Config projection: `../../src/Agent/AutopilotMonitor.Agent.V2.Core/Configuration/RemoteConfigMerger.cs`
+* Backend serve + ConfigVersion: `../../src/Backend/AutopilotMonitor.Functions/Functions/Config/GetAgentConfigFunction.cs`
+* Phase scoping / emit mode background: `../rules/gather-rule-phase-scoping.md`

docs/index.md

@@ -20,6 +20,7 @@ https://docs.autopilotmonitor.com (separate repository).
 * [V2 Agent](agent/index.md) - How the on-device agent works: [runtime overview](agent/overview.md), [decision engine](agent/decision-engine.md) (reducer, signals, completion arms), [logs & persistence](agent/logs-and-persistence.md) (signal log, snapshot, crash recovery), [Hello wizard un-skip](agent/hello-wizard-unskip.md) (why a single "WHfB disabled" read never decides completion), [Autopilot ZTD diagnostics](agent/autopilot-ztd-diagnostics.md) (event IDs, diagnostic registry, endpoints, error-code map).
 * [Build Counter Blob](agent/build-counter-blob.md) - How agent build numbers are minted: shared counter blob with ETag-CAS so local and CI builds never collide; CI additionally attests build provenance (Sigstore).
 * [Agent Endpoint Migration](agent/endpoint-migration.md) - How the backend re-homes agents to a new API base URL via the config channel (backend move or per-tenant region move): live-fetch-only, allowlist-validated on both sides, one hop, kill wins.
+* [Gather Rule Debug Log](agent/gather-rule-debug-log.md) - EnableGatherRuleDebugLog (ConfigVersion 36): the per-tenant local trace file that explains every gather-rule evaluation decision — scope skips, on_change suppression, empty collector results, logparser position/parse-mode outcomes — for rules that produce no timeline events.
 * [MDM Reboot Coalescing](agent/mdm-reboot-coalescing.md) - Attributing the mid-ESP coalesced reboot ("second sign-in") to the device-assigned policy URIs that forced it: aggregated DM-Enterprise 2800 observations (neutral, flush-time watermark) + the ANALYZE-ESP-005 advisory gated on an actually-observed reboot.
 * [Secure Boot CA-2023 Detection](agent/secureboot-ca2023-detection.md) - Why ANALYZE-SEC-001 v3 reads the UEFI db/KEK variables directly instead of trusting the SecureBoot\Servicing registry, and how the one-sided uefiCa2023FirmwareConfirmed marker plus a not_exists precondition give absence-tolerant suppression across old and new agents.
 * [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.
@@ -43,7 +44,7 @@ https://docs.autopilotmonitor.com (separate repository).
 
 # Web Portal
 
-* [Portal Navigation Prefetch & the SWA Runtime Bottleneck](web/portal-navigation-prefetch.md) - Why every navigation Link sets `prefetch={false}`: the App Router's viewport prefetch fans out one RSC request per visible link against an HTTP/1.1 Static Web Apps runtime, and its latency tail starves the six connections that also serve the document and the route chunks. Includes where browser telemetry actually lives.
+* [Portal Navigation Prefetch & the SWA Runtime Bottleneck](web/portal-navigation-prefetch.md) - Why every navigation Link sets `prefetch={false}`: the App Router's viewport prefetch fans out one RSC request per visible link and the Static Web Apps SSR runtime queues them server-side into a multi-minute tail. Records the follow-up measurement (the Standard plan changed nothing; the prefetch storm was an accidental keep-alive), where browser telemetry actually lives, and why this curl build cannot be trusted for HTTP versions.
 
 # Security & Identity
 

docs/log.md

@@ -1,8 +1,16 @@
 # Log
 
+## 2026-07-28
+
+* **Update**: `agent/autopilot-ztd-diagnostics.md` — presentation layer for the startup error backfill (customer feedback: an unannounced wall of pre-agent Error events with a single identical timestamp read like a live failure). Agent: the backfill scan now buffers the capped record set, emits an Info summary event first (`modern_deployment_log`, `backfillSummary: true` + `replayedCount`/`droppedOverCap`/`lookbackMinutes`), then replays oldest-first so the timeline sequence follows event-log chronology. Web: `EventTimeline.tsx` badges `backfilled: true` events („⟲ Backfilled", tooltip) and renders the original `timeCreated` as the row time with a "(reported …)" suffix plus a `Recorded` metadata line — works retroactively for already-stored events. Severity is deliberately not downgraded.
+
+* **Creation**: Added `agent/gather-rule-debug-log.md` — the new per-tenant setting `EnableGatherRuleDebugLog` (ConfigVersion 35 → 36, portal toggle under Settings → Agent, `EnableImeMatchLog`-style bool→path projection in `RemoteConfigMerger`). When enabled, the agent writes `%ProgramData%\AutopilotMonitor\Logs\gather_rules_debug.log`: one pipe-delimited line per evaluation decision across ten previously silent "produced nothing" exits — disabled rules, `interval` without `intervalSeconds` (never runs), the first-tick-after-one-full-interval window, phase-scope skips incl. `currentPhase=Unknown`, per-(rule, phase) dedup, empty collector results (`emitOnlyIfExists`), `on_change` hash suppression (hash prefix + streak), guard blocks, logparser per-file outcomes (position skips, parse failures with a `format=text` hint when every line fails CMTrace parsing, `maxLines`/wildcard caps), and full exception stacks that the agent log drops. 10 MB cap + one `.old` generation; no hot-reload (per-enrollment lifecycle); flag survives the offline config cache; `--run-gather-rules` always traces and echoes under `--console`; zero-rules delivery leaves a one-line file instead of nothing. Side fix: `GatherRuleExecutorHost` now passes the logger into `InformationalEventPost`, so gather-event emissions appear in the agent DEBUG log.
+
+* **Correction + Update**: `web/portal-navigation-prefetch.md`. The HTTP/1.1 claim in the 2026-07-27 entry below is **wrong** and has been struck from the document: `portal.autopilotmonitor.com` negotiates **h2**, verified by `openssl s_client -alpn h2,http/1.1` and a .NET `HttpClient` returning `HTTP/2.0`. The false reading came from the Windows/Schannel curl build in this environment, which has no HTTP/2 support and therefore always reports `1.1` — do not use it to determine HTTP versions. There is no six-connection cap in play; the queue is server-side in the SWA SSR runtime, which does not change the fix or the evidence, only the mechanism. Added an `Outcome` section with 20 h of post-change telemetry: the Free → Standard plan change (16:02:44 UTC) produced **no measurable latency gain** once stratified by the gap to the previous request (p50 Free → Standard: `<10s` 85 → 95 ms, `5-30min` 429 → 441 ms; tail rates 1.64 %/0.374 % over 2 s/10 s vs 6 and 1 events at n = 258 against 4.2 and 1.0 expected; `browserTimings` Mann-Whitney z = −0.24, p = 0.81). The freezes were removed by `prefetch={false}` (16:34:13 UTC): worst `browserTimings.totalDuration` 225,277 → 4,856 ms. The prefetch storm was also an **accidental keep-alive** — requests under 10 s apart fell from 85 % to 46 %, and on the identical never-cacheable `/sessions/{id}` route the median rose 87 → 211 ms and p90 465 → 1,480 ms, with one 11,441 ms abandoned request (`resultCode 0`) after 517 minutes idle. Synthetic bursts warm the runtime and must not be used to benchmark this (round 1 p50 288 ms vs rounds 4–25 p50 113 ms).
+
 ## 2026-07-27
 
-* **Creation**: Added `web/portal-navigation-prefetch.md` (and a `Web Portal` section to the index) — root cause of the minute-long portal freezes. `GlobalSidebar` and `Navbar` render the whole navigation on every page, so the App Router's default viewport prefetch issued one `?_rsc=` request per visible link against `portal.autopilotmonitor.com` (~10,400 in 14 days). That origin serves the document, the route chunks and the RSC payloads over **HTTP/1.1**, so the six-connection-per-origin cap applies; when the Static Web Apps managed runtime queued the prefetches (p50 91 ms, p95 896 ms, but max 234 s / 21 samples over 30 s), the in-flight prefetches held every socket and the navigation the user wanted could not get one. Measured on the 2026-07-27 17:25 CEST incident: `/admin/presence?_rsc=` 151 s, three siblings finishing within 340 ms of each other at ~37.5 s, all `200`, while the backend API answered in 1.6–2.2 s and `browserTimings` showed `networkDuration` 16 ms against `processingDuration` 225 s. Every navigation Link now sets `prefetch={false}` — these routes are client components behind `ProtectedRoute` that fetch their own data, so the prefetched RSC payload carried no benefit. The doc also records that browser telemetry lives in a **separate** App Insights resource (`AUTOPILOT_MONITOR_WEB_APPINSIGHTS_ID`) that the MCP `query_backend_logs` tool cannot reach, which is why the freezes left no trace in the backend logs.
+* **Creation**: Added `web/portal-navigation-prefetch.md` (and a `Web Portal` section to the index) — root cause of the minute-long portal freezes. `GlobalSidebar` and `Navbar` render the whole navigation on every page, so the App Router's default viewport prefetch issued one `?_rsc=` request per visible link against `portal.autopilotmonitor.com` (~10,400 in 14 days). *(The original entry attributed the freeze to HTTP/1.1 and a six-connection-per-origin cap — see the 2026-07-28 correction; the queue is server-side.)* When the Static Web Apps managed runtime queued the prefetches (p50 91 ms, p95 896 ms, but max 234 s / 21 samples over 30 s), the navigation the user wanted was stuck behind that queue. Measured on the 2026-07-27 17:25 CEST incident: `/admin/presence?_rsc=` 151 s, three siblings finishing within 340 ms of each other at ~37.5 s, all `200`, while the backend API answered in 1.6–2.2 s and `browserTimings` showed `networkDuration` 16 ms against `processingDuration` 225 s. Every navigation Link now sets `prefetch={false}` — these routes are client components behind `ProtectedRoute` that fetch their own data, so the prefetched RSC payload carried no benefit. The doc also records that browser telemetry lives in a **separate** App Insights resource (`AUTOPILOT_MONITOR_WEB_APPINSIGHTS_ID`) that the MCP `query_backend_logs` tool cannot reach, which is why the freezes left no trace in the backend logs.
 
 * **Creation**: Added `backend/rule-regression-radar.md` — F3 regression radar (analyze rules only; gather rules wait for their per-batch stats dedup fix): per (tenant, rule) daily hit rate from `RuleStats`, firing only when the trailing 7-day window has ≥5 hit sessions and ≥20 evaluated sessions, the rate is ≥2× the prior 28-day baseline AND the Wilson 95 % intervals are disjoint (deterministic `MetricsMath` primitive with hand-computed test vectors). Suppressed for deleted rules, rules younger than baseline+window (`CreatedAt` grace), rules edited inside the window (`UpdatedAt`), empty baselines, and the `RuleRegressionRadarDisabled` app-setting kill switch. Alert episodes live as `ruleregression|{ruleId}` tracker rows (one bell + one `RuleFrequencyRegression` ops event per episode; numbers refreshed while active; re-armed under 1.5× baseline, on fire-stop, or by the 30-day tracker retention). On-fire dimension correlation over osBuild/model/agentVersion/imeVersion with the "correlated, not necessarily causal" wording contract. Surfaces: `regressions[]` in the rule-stats response (MCP inherits), the analyze-rules page's 30-day sparkline and regression badge.
 

docs/web/portal-navigation-prefetch.md

@@ -1,7 +1,7 @@
 ---
 type: Concept
 title: Portal Navigation Prefetch & the SWA Runtime Bottleneck
-description: Why every navigation Link in the portal sets prefetch={false} — the App Router's viewport prefetch fires one RSC request per visible link against an HTTP/1.1 Static Web Apps runtime, and its latency tail starves the connection pool that serves the document and the route chunks.
+description: Why every navigation Link in the portal sets prefetch={false} — the App Router's viewport prefetch fires one RSC request per visible link, and the Static Web Apps SSR runtime queues them server-side into a multi-minute latency tail. Also records what the follow-up measurement showed about the Standard SKU and the keep-alive side effect.
 resource: src/Web/autopilot-monitor-web/components/GlobalSidebar.tsx
 tags:
   - web
@@ -25,21 +25,26 @@ it enters the viewport.
 
 # Mechanism
 
-Three properties combine into a portal-wide freeze:
+Two properties combine into a portal-wide freeze:
 
 1. **Fan-out.** The navigation is fully rendered on each page load, so a single navigation issues one
    RSC request per visible link — measured at ~10,400 requests over 14 days.
-2. **Shared origin over HTTP/1.1.** `portal.autopilotmonitor.com` serves the document, the JS route
-   chunks *and* the RSC payloads, and it negotiates HTTP/1.1 — not HTTP/2. Browsers cap concurrent
-   connections per origin at six.
-3. **A heavy latency tail on the SSR runtime.** RSC responses are prerendered and edge-cached
+2. **A heavy latency tail on the SSR runtime.** RSC responses are prerendered and edge-cached
    (`x-nextjs-cache: HIT`, `s-maxage=31536000`), so the median is fast. On a cache miss or cold start
-   the Static Web Apps managed runtime queues them.
+   the Static Web Apps managed runtime queues them **server-side**, and the queue drains all at once.
 
-When the tail hits, the in-flight prefetches hold all six connections. The document request and the
-route chunks of the page the user actually wants then have no socket available, and the tab shows a
-loading spinner or a blank page until the queue drains. Nothing fails — the requests eventually
-return `200`, which is why the failure leaves no error trace anywhere.
+The navigation the user wants is then stuck behind that queue and the tab shows a loading spinner or a
+blank page until it drains. Nothing fails — the requests eventually return `200`, which is why the
+failure leaves no error trace anywhere.
+
+> **Correction (2026-07-28).** The original version of this document named a third property: that
+> `portal.autopilotmonitor.com` negotiates HTTP/1.1 and the prefetches exhaust the six-connection
+> browser cap. **That is wrong.** It came from `curl -w '%{http_version}'` on a Windows build of curl
+> whose Schannel backend has no HTTP/2 support, so it can only ever report `1.1`. ALPN says otherwise:
+> `openssl s_client -alpn h2,http/1.1` negotiates **h2** on the portal host, confirmed by a .NET
+> `HttpClient` request returning `HTTP/2.0`. There is no six-connection cap and connection starvation
+> was never the mechanism — the queue is server-side. Verify HTTP versions with `openssl s_client
+> -alpn` or `HttpClient`, never with this curl build.
 
 # Evidence
 
@@ -62,6 +67,33 @@ document immediately and the browser then waited nearly four minutes for the `lo
 Fourteen-day distribution of RSC prefetches: n = 10,428, p50 = 91 ms, p95 = 896 ms, max = 234,230 ms,
 38 over 10 s, 21 over 30 s.
 
+# Outcome, measured 2026-07-28
+
+Two changes landed within half an hour of each other on 2026-07-27: the SWA plan went Free → Standard
+at 16:02:44 UTC, and `prefetch={false}` went live at 16:34:13 UTC. Twenty hours of production
+telemetry separate their effects.
+
+**The Standard plan produced no measurable latency gain.** Latency is governed almost entirely by the
+gap to the previous request — the SSR runtime cools down — so raw percentiles only measure the traffic
+mix. Stratified by that gap, the two eras are indistinguishable (p50, Free → Standard): `<10s`
+85 → 95 ms · `10-60s` 100 → 117 ms · `1-5min` 295 → 310 ms · `5-30min` 429 → 441 ms. Tail rates match
+too: Free ran 1.64 % over 2 s and 0.374 % over 10 s (n = 10,163); Standard produced 6 and 1 events at
+n = 258 against 4.2 and 1.0 expected. `browserTimings.totalDuration` by Mann-Whitney: n = 436 vs 48,
+z = −0.24, **p = 0.81**.
+
+**The prefetch fix is what removed the freezes** — worst `browserTimings.totalDuration` fell from
+225,277 ms to 4,856 ms, and the 30-second events stopped.
+
+**It also removed an accidental keep-alive.** The prefetch storm kept the SSR runtime warm: 85 % of
+requests used to arrive less than 10 s apart, now 46 % do. On an identical never-cacheable route
+(`/sessions/{id}`) the median rose from 87 ms to 211 ms and p90 from 465 ms to 1,480 ms. After 517
+minutes idle, one request took 11,441 ms and was abandoned (`resultCode 0`). The trade — minute-long
+freezes gone, ~150 ms added to a cold navigation — is worth it, but it is a trade.
+
+Do not benchmark this with a synthetic burst. Firing requests in quick succession warms the runtime
+and measures the best case: in a 25-round `curl --parallel-max 6` run, round 1 came in at p50 288 ms
+and rounds 4–25 at p50 113 ms.
+
 # Diagnosing this class of problem
 
 The backend Application Insights resource is the wrong place to look — a freeze appears there as an

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Configuration/RemoteConfigMergerTests.cs

@@ -285,6 +285,54 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Configuration
             Assert.Equal(@"C:\Temp\custom-ime.log", agent.ImeMatchLogPath);
         }
 
+        [Fact]
+        public void Merge_maps_enable_gather_rule_debug_log_true_to_default_path()
+        {
+            var agent = NewAgentConfig();
+            agent.GatherRuleDebugLogPath = null;
+
+            var remote = FullRemote();
+            remote.EnableGatherRuleDebugLog = true;
+
+            RemoteConfigMerger.Merge(agent, remote);
+
+            Assert.False(string.IsNullOrEmpty(agent.GatherRuleDebugLogPath));
+            Assert.Equal(
+                Environment.ExpandEnvironmentVariables(Constants.GatherRuleDebugLogPath),
+                agent.GatherRuleDebugLogPath);
+        }
+
+        [Fact]
+        public void Merge_maps_enable_gather_rule_debug_log_false_clears_path()
+        {
+            var agent = NewAgentConfig();
+            agent.GatherRuleDebugLogPath = Environment.ExpandEnvironmentVariables(Constants.GatherRuleDebugLogPath);
+
+            var remote = FullRemote();
+            remote.EnableGatherRuleDebugLog = false;
+
+            RemoteConfigMerger.Merge(agent, remote);
+
+            Assert.Null(agent.GatherRuleDebugLogPath);
+        }
+
+        [Fact]
+        public void Merge_preserves_custom_gather_rule_debug_log_path_when_remote_disables()
+        {
+            // A dev-time --gather-debug-log <custom> override seeds a non-default path on the
+            // AgentConfiguration. When the tenant remote flips EnableGatherRuleDebugLog off we
+            // keep the custom path rather than clobbering a deliberate dev override.
+            var agent = NewAgentConfig();
+            agent.GatherRuleDebugLogPath = @"C:\Temp\custom-gather.log";
+
+            var remote = FullRemote();
+            remote.EnableGatherRuleDebugLog = false;
+
+            RemoteConfigMerger.Merge(agent, remote);
+
+            Assert.Equal(@"C:\Temp\custom-gather.log", agent.GatherRuleDebugLogPath);
+        }
+
         // ============================================================= Null / partial tolerance
 
         [Fact]

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Gather/GatherRuleDebugLogTests.cs

@@ -0,0 +1,104 @@
+using System;
+using System.IO;
+using System.Linq;
+using AutopilotMonitor.Agent.V2.Core.Logging;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather;
+using AutopilotMonitor.Agent.V2.Core.Tests.Harness;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Gather
+{
+    /// <summary>
+    /// Writer unit tests for <see cref="GatherRuleDebugLog"/>: line format, lazy directory
+    /// creation, size-cap rotation, and the null-writer no-op path on the context.
+    /// </summary>
+    public sealed class GatherRuleDebugLogTests : IDisposable
+    {
+        private readonly TempDirectory _tmp = new TempDirectory();
+        private readonly AgentLogger _logger;
+
+        public GatherRuleDebugLogTests()
+        {
+            _logger = new AgentLogger(_tmp.Path, AgentLogLevel.Info);
+        }
+
+        public void Dispose() => _tmp.Dispose();
+
+        private string LogPath => Path.Combine(_tmp.Path, "sub", "gather_rules_debug.log");
+
+        [Fact]
+        public void Write_produces_pipe_delimited_line_and_creates_directory_lazily()
+        {
+            var log = new GatherRuleDebugLog(LogPath, _logger);
+            Assert.False(File.Exists(LogPath)); // lazy — nothing until the first write
+
+            log.Write("RULE-1", GatherRuleDebugLog.StageScope, "skipped: out of scope");
+
+            var lines = File.ReadAllLines(LogPath);
+            Assert.Equal(2, lines.Length); // header + entry
+            Assert.Contains("| - | config | -- gather rule debug log started --", lines[0]);
+            var parts = lines[1].Split(new[] { " | " }, StringSplitOptions.None);
+            Assert.Equal(4, parts.Length);
+            Assert.Equal("RULE-1", parts[1]);
+            Assert.Equal("scope", parts[2]);
+            Assert.Equal("skipped: out of scope", parts[3]);
+        }
+
+        [Fact]
+        public void Write_flattens_newlines_except_for_error_stage()
+        {
+            var log = new GatherRuleDebugLog(LogPath, _logger);
+            log.Write("RULE-1", GatherRuleDebugLog.StageCollector, "line1\r\nline2");
+            log.Write("RULE-1", GatherRuleDebugLog.StageError, "boom\r\n   at Frame()");
+
+            var content = File.ReadAllText(LogPath);
+            Assert.Contains("line1 line2", content);
+            Assert.Contains("   at Frame()", content); // error stage keeps the stack multi-line
+        }
+
+        [Fact]
+        public void Write_null_ruleId_renders_dash()
+        {
+            var log = new GatherRuleDebugLog(LogPath, _logger);
+            log.Write(null, GatherRuleDebugLog.StageConfig, "no rules delivered");
+
+            Assert.Contains(" | - | config | no rules delivered", File.ReadAllText(LogPath));
+        }
+
+        [Fact]
+        public void Write_rotates_once_when_file_exceeds_cap()
+        {
+            var log = new GatherRuleDebugLog(LogPath, _logger, maxBytes: 512);
+            for (int i = 0; i < 20; i++)
+                log.Write("RULE-1", GatherRuleDebugLog.StageExec, new string('x', 100));
+
+            var oldPath = Path.Combine(Path.GetDirectoryName(LogPath), "gather_rules_debug.old.log");
+            Assert.True(File.Exists(oldPath), "expected one .old rotation generation");
+            Assert.True(File.Exists(LogPath));
+            Assert.Contains("-- rotated", File.ReadAllText(LogPath) + File.ReadAllText(oldPath));
+            // Never more than one .old generation
+            Assert.Single(Directory.GetFiles(Path.GetDirectoryName(LogPath), "*.old.log"));
+        }
+
+        [Fact]
+        public void WriteStandalone_writes_single_config_line()
+        {
+            GatherRuleDebugLog.WriteStandalone(LogPath, "no gather rules delivered by backend — nothing to execute", _logger);
+
+            var lines = File.ReadAllLines(LogPath);
+            Assert.Contains(lines, l => l.Contains("no gather rules delivered by backend"));
+        }
+
+        [Fact]
+        public void Context_DebugLog_is_noop_without_writer()
+        {
+            var context = new GatherRuleContext(
+                _logger, "sess", "tenant", _ => { }, null, new LogFilePositionTracker());
+
+            context.DebugLog("RULE-1", GatherRuleDebugLog.StageScope, "should not throw, should not write");
+
+            Assert.False(File.Exists(LogPath));
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Gather/GatherRuleExecutorDebugLogTests.cs

@@ -0,0 +1,156 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using AutopilotMonitor.Agent.V2.Core.Logging;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather;
+using AutopilotMonitor.Agent.V2.Core.Tests.Harness;
+using AutopilotMonitor.Shared.Models;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Gather
+{
+    /// <summary>
+    /// Debug-trace coverage of <see cref="GatherRuleExecutor"/> (EnableGatherRuleDebugLog):
+    /// every "silently produced nothing" outcome must leave an explanatory line in the trace
+    /// file — registration summary, missing interval, scope skips, on_change suppression,
+    /// empty collector results.
+    /// </summary>
+    [Collection("SerialThreading")] // startup rules execute on the shared ThreadPool
+    public sealed class GatherRuleExecutorDebugLogTests : IDisposable
+    {
+        private readonly TempDirectory _tmp = new TempDirectory();
+        private readonly GatherRuleExecutor _executor;
+        private readonly string _debugLogPath;
+
+        private const string AbsentPath =
+            "HKLM\\SOFTWARE\\AutopilotMonitorTests\\DefinitelyAbsent_7e3a1f4b-0000-0000-0000-000000000000";
+
+        public GatherRuleExecutorDebugLogTests()
+        {
+            var logger = new AgentLogger(_tmp.Path, AgentLogLevel.Info);
+            _debugLogPath = Path.Combine(_tmp.Path, "gather_rules_debug.log");
+            _executor = new GatherRuleExecutor(
+                "sess", "tenant", _ => { }, logger,
+                debugLogPath: _debugLogPath)
+            {
+                UnrestrictedMode = true
+            };
+        }
+
+        public void Dispose()
+        {
+            _executor.Dispose();
+            _tmp.Dispose();
+        }
+
+        private string TraceContent() => File.Exists(_debugLogPath) ? File.ReadAllText(_debugLogPath) : string.Empty;
+
+        private static GatherRule Rule(string id, Action<GatherRule>? mutate = null)
+        {
+            var rule = new GatherRule
+            {
+                RuleId = id,
+                Title = id,
+                CollectorType = "registry",
+                Target = AbsentPath,
+                Trigger = "startup",
+                OutputEventType = "gather_test",
+                Enabled = true,
+            };
+            mutate?.Invoke(rule);
+            return rule;
+        }
+
+        [Fact]
+        public void UpdateRules_writes_registration_summary_per_rule()
+        {
+            _executor.UpdateRules(new List<GatherRule>
+            {
+                Rule("GATHER-REG-001", r => { r.Trigger = "interval"; r.IntervalSeconds = 3600; r.EmitMode = "on_change"; }),
+                Rule("GATHER-REG-002", r => r.Enabled = false),
+            });
+            _executor.WaitForStartupRules(30);
+
+            var trace = TraceContent();
+            Assert.Contains("GATHER-REG-001 | config | registered: trigger=interval, collector=registry", trace);
+            Assert.Contains("emitMode=on_change", trace);
+            Assert.Contains("interval=3600s", trace);
+            Assert.Contains("GATHER-REG-002 | config | rule disabled — will never run", trace);
+            Assert.Contains("interval timer scheduled every 3600s (first run after one full interval", trace);
+        }
+
+        [Fact]
+        public void UpdateRules_flags_interval_rule_without_intervalSeconds()
+        {
+            _executor.UpdateRules(new List<GatherRule>
+            {
+                Rule("GATHER-NOINT-001", r => { r.Trigger = "interval"; r.IntervalSeconds = null; }),
+            });
+
+            Assert.Contains("GATHER-NOINT-001 | error | trigger=interval but intervalSeconds is missing — rule will NEVER run",
+                TraceContent());
+        }
+
+        [Fact]
+        public void ScopedRule_skip_traces_unknown_phase_reason()
+        {
+            var rule = Rule("GATHER-SCOPE-001", r => { r.Trigger = "interval"; r.IntervalSeconds = 3600; r.ActivePhases = new List<string> { "DeviceSetup" }; });
+            _executor.UpdateRules(new List<GatherRule> { rule });
+
+            // Synchronous internal check mirrors the timer-tick gate; the reason must name Unknown.
+            string reason;
+            Assert.False(_executor.IsRuleInScope(rule, out reason));
+            Assert.Contains("currentPhase=Unknown", reason);
+        }
+
+        [Fact]
+        public void ScopedStartupRule_deferral_is_traced()
+        {
+            _executor.UpdateRules(new List<GatherRule>
+            {
+                Rule("GATHER-DEFER-001", r => r.ActivePhases = new List<string> { "DeviceSetup" }),
+            });
+
+            Assert.Contains("GATHER-DEFER-001 | scope | startup rule deferred — currentPhase=Unknown", TraceContent());
+        }
+
+        [Fact]
+        public void OnChange_suppression_and_reemission_are_traced()
+        {
+            var rule = Rule("GATHER-OC-001", r => { r.Trigger = "interval"; r.IntervalSeconds = 3600; r.EmitMode = "on_change"; });
+            _executor.UpdateRules(new List<GatherRule> { rule });
+
+            string hashPrefix;
+            int streak;
+            var first = new Dictionary<string, object> { ["exists"] = false };
+            Assert.True(_executor.ShouldEmitOnChange(rule, first, out hashPrefix, out streak));
+            Assert.Equal(0, streak);
+            Assert.False(string.IsNullOrEmpty(hashPrefix));
+
+            Assert.False(_executor.ShouldEmitOnChange(rule, new Dictionary<string, object> { ["exists"] = false }, out hashPrefix, out streak));
+            Assert.Equal(1, streak);
+            Assert.False(_executor.ShouldEmitOnChange(rule, new Dictionary<string, object> { ["exists"] = false }, out hashPrefix, out streak));
+            Assert.Equal(2, streak);
+
+            var changed = new Dictionary<string, object> { ["exists"] = true };
+            Assert.True(_executor.ShouldEmitOnChange(rule, changed, out hashPrefix, out streak));
+            Assert.Equal(2, streak); // the streak that just ended
+            Assert.Equal(2, changed["suppressedPolls"]);
+        }
+
+        [Fact]
+        public void EmptyCollectorResult_is_traced_via_startup_execution()
+        {
+            _executor.UpdateRules(new List<GatherRule>
+            {
+                Rule("GATHER-EMPTY-001", r => r.Parameters = new Dictionary<string, string> { ["emitOnlyIfExists"] = "true" }),
+            });
+            Assert.True(_executor.WaitForStartupRules(30));
+
+            var trace = TraceContent();
+            Assert.Contains("GATHER-EMPTY-001 | exec | executing: collector=registry", trace);
+            Assert.Contains("GATHER-EMPTY-001 | collector | registry key/value not found", trace);
+            Assert.Contains("GATHER-EMPTY-001 | collector | collector returned EMPTY result — nothing emitted", trace);
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Gather/LogParserCollectorDebugLogTests.cs

@@ -0,0 +1,121 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using AutopilotMonitor.Agent.V2.Core.Logging;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors;
+using AutopilotMonitor.Agent.V2.Core.Tests.Harness;
+using AutopilotMonitor.Shared.Models;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Gather
+{
+    /// <summary>
+    /// Debug-trace coverage of <see cref="LogParserCollector"/>: the classic
+    /// "rule delivers nothing" cases must be explained in the trace — zero matches,
+    /// position-tracker skips, and plain-text logs parsed in the default cmtrace mode.
+    /// </summary>
+    public sealed class LogParserCollectorDebugLogTests : IDisposable
+    {
+        private readonly TempDirectory _tmp = new TempDirectory();
+        private readonly List<EnrollmentEvent> _events = new List<EnrollmentEvent>();
+        private readonly GatherRuleContext _context;
+        private readonly string _debugLogPath;
+
+        // %TEMP% lives under C:\Users (hard-blocked) — parse targets sit beside the
+        // test assembly instead, admitted via UnrestrictedMode.
+        private readonly string _outsideUsers = Path.Combine(
+            AppContext.BaseDirectory, "gather-debug-tests-" + Guid.NewGuid().ToString("N"));
+
+        public LogParserCollectorDebugLogTests()
+        {
+            Directory.CreateDirectory(_outsideUsers);
+            var logger = new AgentLogger(_tmp.Path, AgentLogLevel.Info);
+            _debugLogPath = Path.Combine(_tmp.Path, "gather_rules_debug.log");
+            _context = new GatherRuleContext(
+                logger, "sess", "tenant",
+                evt => _events.Add(evt),
+                null,
+                new LogFilePositionTracker(),
+                new GatherRuleDebugLog(_debugLogPath, logger))
+            {
+                UnrestrictedMode = true
+            };
+        }
+
+        public void Dispose()
+        {
+            _tmp.Dispose();
+            try { Directory.Delete(_outsideUsers, recursive: true); } catch { /* best effort */ }
+        }
+
+        private string TraceContent() => File.Exists(_debugLogPath) ? File.ReadAllText(_debugLogPath) : string.Empty;
+
+        private static GatherRule Rule(string target, string pattern, string? format = null) => new GatherRule
+        {
+            RuleId = "GATHER-LP-DEBUG",
+            Title = "logparser debug test",
+            CollectorType = "logparser",
+            Target = target,
+            Parameters = format == null
+                ? new Dictionary<string, string> { ["pattern"] = pattern }
+                : new Dictionary<string, string> { ["pattern"] = pattern, ["format"] = format },
+            Trigger = "startup",
+            OutputEventType = "logparser_debug_test",
+        };
+
+        [Fact]
+        public void ZeroMatches_writes_per_file_outcome_line()
+        {
+            var path = Path.Combine(_outsideUsers, "app.log");
+            File.WriteAllText(path, "nothing interesting\nstill nothing\n");
+
+            new LogParserCollector().Execute(Rule(path, "WILL_NEVER_MATCH_[0-9]+", format: "text"), _context);
+
+            Assert.Empty(_events);
+            var trace = TraceContent();
+            Assert.Contains("app.log: read 2 lines", trace);
+            Assert.Contains("matched 0", trace);
+            Assert.Contains("mode=text", trace);
+        }
+
+        [Fact]
+        public void SecondRun_without_new_content_traces_position_skip()
+        {
+            var path = Path.Combine(_outsideUsers, "twice.log");
+            File.WriteAllText(path, "one line\n");
+            var rule = Rule(path, "one", format: "text");
+
+            var collector = new LogParserCollector();
+            collector.Execute(rule, _context);   // reads the file, advances the position
+            collector.Execute(rule, _context);   // nothing new
+
+            Assert.Contains("twice.log: no new content (position", TraceContent());
+        }
+
+        [Fact]
+        public void PlainTextFile_in_default_cmtrace_mode_gets_format_hint()
+        {
+            var path = Path.Combine(_outsideUsers, "plain.log");
+            File.WriteAllText(path, "plain line one\nplain line two\n");
+
+            new LogParserCollector().Execute(Rule(path, "plain"), _context); // default = cmtrace mode
+
+            Assert.Empty(_events);
+            var trace = TraceContent();
+            Assert.Contains("parseFailures=2", trace);
+            Assert.Contains("every line failed CMTrace parsing — if this is a plain-text log, set parameter format=text", trace);
+        }
+
+        [Fact]
+        public void MissingFile_traces_no_files_matched()
+        {
+            var path = Path.Combine(_outsideUsers, "does-not-exist.log");
+
+            new LogParserCollector().Execute(Rule(path, "x", format: "text"), _context);
+
+            Assert.Contains("no files matched target", TraceContent());
+        }
+    }
+}

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

@@ -226,6 +226,95 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Runtime
             return archive.Entries.Select(e => e.FullName).ToArray();
         }
 
+        private static string ZipEntryText(byte[] zipBytes, string entryName)
+        {
+            using var ms = new MemoryStream(zipBytes);
+            using var archive = new ZipArchive(ms, ZipArchiveMode.Read);
+            var entry = archive.GetEntry(entryName);
+            Assert.NotNull(entry);
+            using var reader = new StreamReader(entry!.Open(), Encoding.UTF8);
+            return reader.ReadToEnd();
+        }
+
+        // ── Nullable outcome (on-demand mid-session) — gate + sessioninfo semantics ──
+
+        /// <summary>
+        /// Sentinel subclass: throws before any HTTP so gate-pass-through is observable as a
+        /// non-null error result (a skip returns null BEFORE the archive is ever built).
+        /// </summary>
+        private sealed class ThrowOnBuildService : DiagnosticsPackageService
+        {
+            public ThrowOnBuildService(AgentConfiguration cfg, AgentLogger logger, BackendApiClient api)
+                : base(cfg, logger, api) { }
+            internal override byte[] BuildArchiveBytes(bool? enrollmentSucceeded) =>
+                throw new System.InvalidOperationException("gate-passed-sentinel");
+        }
+
+        private static DiagnosticsPackageService BuildGateProbe(AgentLogger logger, string mode)
+        {
+            var cfg = Cfg();
+            cfg.DiagnosticsUploadEnabled = true;
+            cfg.DiagnosticsUploadMode = mode;
+            var apiClient = new BackendApiClient(
+                httpClient: new System.Net.Http.HttpClient(),
+                baseUrl: "http://localhost",
+                manufacturer: string.Empty,
+                model: string.Empty,
+                serialNumber: string.Empty,
+                useBootstrapTokenAuth: false,
+                bootstrapToken: null,
+                agentVersion: "0.0.0",
+                logger: logger);
+            return new ThrowOnBuildService(cfg, logger, apiClient);
+        }
+
+        [Fact]
+        public async System.Threading.Tasks.Task CreateAndUploadAsync_null_outcome_passes_OnFailure_gate()
+        {
+            // 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.
+            using var rig = new Rig();
+            var result = await BuildGateProbe(rig.Logger, "OnFailure")
+                .CreateAndUploadAsync(enrollmentSucceeded: null, fileNameSuffix: "server-requested");
+
+            Assert.NotNull(result);
+            Assert.Equal("gate-passed-sentinel", result!.ErrorCode);
+        }
+
+        [Fact]
+        public async System.Threading.Tasks.Task CreateAndUploadAsync_known_success_still_skipped_by_OnFailure_gate()
+        {
+            using var rig = new Rig();
+            var result = await BuildGateProbe(rig.Logger, "OnFailure")
+                .CreateAndUploadAsync(enrollmentSucceeded: true);
+
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public async System.Threading.Tasks.Task CreateAndUploadAsync_null_outcome_still_blocked_by_mode_Off()
+        {
+            using var rig = new Rig();
+            var result = await BuildGateProbe(rig.Logger, "Off")
+                .CreateAndUploadAsync(enrollmentSucceeded: null);
+
+            Assert.Null(result);
+        }
+
+        [Theory]
+        [InlineData(true, "Succeeded")]
+        [InlineData(false, "Failed")]
+        [InlineData(null, "In Progress")]
+        public void BuildArchiveBytes_sessioninfo_reflects_nullable_outcome(bool? outcome, string expected)
+        {
+            using var rig = new Rig();
+            var bytes = rig.Build().BuildArchiveBytes(outcome);
+
+            var sessionInfo = ZipEntryText(bytes, "sessioninfo.txt");
+            Assert.Contains($"Enrollment Result: {expected}", sessionInfo);
+        }
+
         // ── BuildBlobUploadUrl — destination-aware URL construction ─────────────────
 
         [Theory]

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/SystemSignals/ModernDeploymentTrackerErrorBackfillTests.cs

@@ -112,6 +112,36 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.SystemSignals
             Assert.Equal(false, data["backfilled"]);
         }
 
+        [Fact]
+        public void ErrorBackfillSummary_EmitsInfoLogEvent_AnnouncingTheReplayBlock()
+        {
+            _tracker.EmitErrorBackfillSummary(replayedCount: 6, droppedOverCap: 0);
+
+            var posted = _sink.Posted.Single(p => p.Kind == DecisionSignalKind.InformationalEvent);
+            Assert.Equal("modern_deployment_log", posted.Payload![SignalPayloadKeys.EventType]);
+
+            var data = Assert.IsAssignableFrom<IReadOnlyDictionary<string, object>>(posted.TypedPayload);
+            Assert.Equal(true, data["backfillSummary"]);
+            Assert.Equal(6, data["replayedCount"]);
+            Assert.Equal(0, data["droppedOverCap"]);
+            Assert.Equal(240, data["lookbackMinutes"]);
+
+            var message = (string)posted.Payload[SignalPayloadKeys.Message];
+            Assert.Contains("Replaying 6 error event(s)", message);
+            Assert.Contains("before the agent started", message);
+            Assert.DoesNotContain("cap", message);
+        }
+
+        [Fact]
+        public void ErrorBackfillSummary_MentionsDroppedRecords_WhenCapWasHit()
+        {
+            _tracker.EmitErrorBackfillSummary(replayedCount: 25, droppedOverCap: 7);
+
+            var posted = _sink.Posted.Single(p => p.Kind == DecisionSignalKind.InformationalEvent);
+            var message = (string)posted.Payload![SignalPayloadKeys.Message];
+            Assert.Contains("7 older record(s) beyond the 25-record cap", message);
+        }
+
         [Fact]
         public void BackfilledHarmlessId_StillRunsThroughRollupSuppression()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Termination/EnrollmentTerminationHandlerTests.cs

@@ -511,6 +511,88 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Termination
                 $"network_bandwidth_estimate (@{bandwidthIdx}) must precede whiteglove_part1_complete (@{part1CompleteIdx}) so the straggler stays in Part 1.");
         }
 
+        // ===================================================== WG Part-1 preprov diagnostics
+        // V1 parity (restored 2026-07-28): the seal exit uploads the diagnostics package as a
+        // pre-provisioning intermediate under the SAME mode gating as the terminal path — the
+        // seal counts as a success, so Always uploads, OnFailure skips (a Part-1 failure
+        // terminates via the regular Failed path, which uploads), Off does nothing.
+
+        [Theory]
+        [InlineData("Always", true, 1)]
+        [InlineData("OnFailure", true, 0)]
+        [InlineData("Off", true, 0)]
+        [InlineData("Always", false, 0)]
+        public void Handle_whiteglove_part1_diagnostics_upload_respects_mode(
+            string mode, bool enabled, int expected)
+        {
+            using var rig = new Rig();
+            rig.State = new DecisionStateBuilder(DecisionState.CreateInitial("S1", "T1")) { Stage = SessionStage.WhiteGloveSealed }.Build();
+            var cfg = rig.BuildConfig(diagEnabled: enabled, diagMode: mode);
+
+            rig.Build(cfg).Handle(sender: null!,
+                Args(EnrollmentTerminationReason.DecisionTerminalStage, EnrollmentTerminationOutcome.Succeeded, SessionStage.WhiteGloveSealed));
+
+            Assert.Equal(expected, rig.DiagnosticsUploads);
+        }
+
+        [Fact]
+        public void Handle_whiteglove_part1_diagnostics_upload_uses_preprov_suffix_and_succeeded_flag()
+        {
+            using var rig = new Rig();
+            rig.State = new DecisionStateBuilder(DecisionState.CreateInitial("S1", "T1")) { Stage = SessionStage.WhiteGloveSealed }.Build();
+            var cfg = rig.BuildConfig(diagEnabled: true, diagMode: "Always");
+
+            rig.Build(cfg).Handle(sender: null!,
+                Args(EnrollmentTerminationReason.DecisionTerminalStage, EnrollmentTerminationOutcome.Succeeded, SessionStage.WhiteGloveSealed));
+
+            Assert.Equal(1, rig.DiagnosticsUploads);
+            Assert.Equal("preprov", rig.LastDiagnosticsSuffix);
+            Assert.Equal(true, rig.LastDiagnosticsSucceededFlag);
+        }
+
+        [Fact]
+        public void Handle_whiteglove_part1_diagnostics_events_precede_part1_complete_marker()
+        {
+            // whiteglove_part1_complete is the authoritative Part-1/Part-2 boundary for the
+            // web split (computeWhiteGloveSplitSequence) — diagnostics_collecting/uploaded
+            // must sequence BEFORE it or they get mis-filed into the resumed Part-2 block.
+            using var rig = new Rig();
+            rig.State = new DecisionStateBuilder(DecisionState.CreateInitial("S1", "T1")) { Stage = SessionStage.WhiteGloveSealed }.Build();
+            rig.DiagnosticsResult = new DiagnosticsUploadResult { BlobName = "diag-preprov.zip" };
+            var cfg = rig.BuildConfig(diagEnabled: true, diagMode: "Always");
+
+            rig.Build(cfg).Handle(sender: null!,
+                Args(EnrollmentTerminationReason.DecisionTerminalStage, EnrollmentTerminationOutcome.Succeeded, SessionStage.WhiteGloveSealed));
+
+            var emitted = rig.EmittedEventTypes.ToList();
+            var collectingIdx = emitted.IndexOf("diagnostics_collecting");
+            var uploadedIdx = emitted.IndexOf("diagnostics_uploaded");
+            var part1CompleteIdx = emitted.IndexOf(Constants.EventTypes.WhiteGlovePart1Complete);
+
+            Assert.True(collectingIdx >= 0, "diagnostics_collecting must have been emitted.");
+            Assert.True(uploadedIdx >= 0, "diagnostics_uploaded must have been emitted.");
+            Assert.True(part1CompleteIdx >= 0, "whiteglove_part1_complete must have been emitted.");
+            Assert.True(uploadedIdx < part1CompleteIdx,
+                $"diagnostics_uploaded (@{uploadedIdx}) must precede whiteglove_part1_complete (@{part1CompleteIdx}) so the upload stays in Part 1.");
+        }
+
+        [Fact]
+        public void Handle_whiteglove_part1_still_skips_cleanup_and_marker_when_diagnostics_enabled()
+        {
+            // The preprov upload must not change the Part-1 exit contract: no self-destruct,
+            // no enrollment-complete.marker, whiteglove.complete still written.
+            using var rig = new Rig();
+            rig.State = new DecisionStateBuilder(DecisionState.CreateInitial("S1", "T1")) { Stage = SessionStage.WhiteGloveSealed }.Build();
+            var cfg = rig.BuildConfig(diagEnabled: true, diagMode: "Always");
+
+            rig.Build(cfg).Handle(sender: null!,
+                Args(EnrollmentTerminationReason.DecisionTerminalStage, EnrollmentTerminationOutcome.Succeeded, SessionStage.WhiteGloveSealed));
+
+            Assert.Equal(0, rig.CleanupService.Invocations);
+            Assert.False(File.Exists(Path.Combine(rig.StateDir, "enrollment-complete.marker")));
+            Assert.True(rig.SessionPersistence.IsWhiteGloveResume());
+        }
+
         [Fact]
         public void Handle_standalone_reboot_fires_when_reboot_enabled_and_no_self_destruct()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core/Configuration/AgentConfiguration.cs

@@ -121,6 +121,13 @@ namespace AutopilotMonitor.Agent.V2.Core.Configuration
         /// </summary>
         public string ImeMatchLogPath { get; set; }
 
+        /// <summary>
+        /// Optional path to write a gather-rule evaluation trace (for debugging).
+        /// If empty, no trace is written. Set from remote config (EnableGatherRuleDebugLog)
+        /// or the --gather-debug-log CLI override.
+        /// </summary>
+        public string GatherRuleDebugLogPath { get; set; }
+
         /// <summary>
         /// Path to directory with real IME log files for log replay.
         /// When set, the agent replays these logs with time compression instead of reading live logs.

src/Agent/AutopilotMonitor.Agent.V2.Core/Configuration/RemoteConfigMerger.cs

@@ -135,6 +135,24 @@ namespace AutopilotMonitor.Agent.V2.Core.Configuration
                 }
             }
 
+            // ---------------- GatherRuleDebugLog: same bool→path projection as ImeMatchLog
+            //                  above. `true` expands Constants.GatherRuleDebugLogPath, `false`
+            //                  nulls the runtime path unless a --gather-debug-log CLI override
+            //                  supplied a non-default path.
+            if (remoteConfig.EnableGatherRuleDebugLog)
+            {
+                agentConfig.GatherRuleDebugLogPath = Environment.ExpandEnvironmentVariables(Constants.GatherRuleDebugLogPath);
+            }
+            else
+            {
+                var defaultGatherDebugPath = Environment.ExpandEnvironmentVariables(Constants.GatherRuleDebugLogPath);
+                if (string.IsNullOrEmpty(agentConfig.GatherRuleDebugLogPath)
+                    || string.Equals(agentConfig.GatherRuleDebugLogPath, defaultGatherDebugPath, StringComparison.OrdinalIgnoreCase))
+                {
+                    agentConfig.GatherRuleDebugLogPath = null;
+                }
+            }
+
             // ---------------- Upload interval / batch — direct, V1 parity (no > 0 gate so a
             //                  misconfigured tenant can in theory break uploads, but this
             //                  surfaces the config bug instead of silently masking it).

src/Agent/AutopilotMonitor.Agent.V2.Core/Configuration/RemoteConfigService.cs

@@ -327,6 +327,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Configuration
                 KeepLogFile = false,
                 EnableGeoLocation = true,
                 EnableImeMatchLog = false,
+                EnableGatherRuleDebugLog = false,
                 Collectors = CollectorConfiguration.CreateDefault(),
                 GatherRules = new System.Collections.Generic.List<GatherRule>(),
                 ImeLogPatterns = new System.Collections.Generic.List<ImeLogPattern>()

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/ModernDeploymentTracker.cs

@@ -631,10 +631,15 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         /// the regular <see cref="ProcessRecord"/> pipeline with isBackfill=true, so they arrive
         /// as modern_deployment_error events carrying backfilled=true plus the original
         /// timeCreated; the event's own timestamp is emission time, so session StartedAt is not
-        /// dragged backwards. Newest-first, capped, watermark-deduped across restarts.
+        /// dragged backwards. The scan reads newest-first (the cap keeps the newest records),
+        /// but replay is buffered so an Info summary event announces the block BEFORE the errors
+        /// hit the timeline (customer feedback 2026-07-28: an unannounced wall of pre-agent
+        /// Error events reads like a live failure) and the records emit oldest-first, giving the
+        /// timeline sequence the original event-log chronology. Watermark-deduped across restarts.
         /// </summary>
         private void BackfillAutopilotErrors()
         {
+            var buffered = new List<EventRecord>();
             try
             {
                 long watermark;
@@ -649,7 +654,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                     ReverseDirection = true
                 };
 
-                int processed = 0, skippedWatermark = 0, droppedOverCap = 0;
+                int skippedWatermark = 0, droppedOverCap = 0;
                 long maxSeen = watermark;
 
                 using (var reader = new EventLogReader(query))
@@ -657,37 +662,48 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                     EventRecord record;
                     while ((record = reader.ReadEvent()) != null)
                     {
-                        using (record)
+                        var recordId = record.RecordId ?? 0;
+                        if (recordId > maxSeen) maxSeen = recordId;
+
+                        if (recordId != 0 && recordId <= watermark)
                         {
-                            var recordId = record.RecordId ?? 0;
-                            if (recordId > maxSeen) maxSeen = recordId;
-
-                            if (recordId != 0 && recordId <= watermark)
-                            {
-                                skippedWatermark++;
-                                continue;
-                            }
-
-                            if (processed >= ErrorBackfillMaxRecords)
-                            {
-                                droppedOverCap++;
-                                continue;
-                            }
-
-                            processed++;
-                            ProcessRecord(record, "Autopilot", AutopilotChannel, isBackfill: true);
+                            skippedWatermark++;
+                            record.Dispose();
+                            continue;
                         }
+
+                        if (buffered.Count >= ErrorBackfillMaxRecords)
+                        {
+                            droppedOverCap++;
+                            record.Dispose();
+                            continue;
+                        }
+
+                        buffered.Add(record);
                     }
                 }
 
                 if (maxSeen > watermark)
                     AdvanceAutopilotErrorWatermark(maxSeen);
 
-                if (processed == 0 && droppedOverCap == 0)
+                if (buffered.Count == 0 && droppedOverCap == 0)
+                {
                     _logger.Debug($"ModernDeployment error backfill: nothing new (skippedByWatermark={skippedWatermark})");
+                }
                 else
-                    _logger.Info($"ModernDeployment error backfill: forwarded {processed} record(s) " +
+                {
+                    EmitErrorBackfillSummary(buffered.Count, droppedOverCap);
+
+                    // Scan buffered newest-first — replay in reverse so the emitted sequence
+                    // follows the original event-log chronology.
+                    for (var i = buffered.Count - 1; i >= 0; i--)
+                    {
+                        ProcessRecord(buffered[i], "Autopilot", AutopilotChannel, isBackfill: true);
+                    }
+
+                    _logger.Info($"ModernDeployment error backfill: forwarded {buffered.Count} record(s) " +
                         $"(skippedByWatermark={skippedWatermark}, droppedOverCap={droppedOverCap})");
+                }
             }
             catch (EventLogNotFoundException)
             {
@@ -701,6 +717,49 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
             {
                 _logger.Warning($"ModernDeployment error backfill failed: {ex.Message}");
             }
+            finally
+            {
+                foreach (var record in buffered)
+                {
+                    try { record.Dispose(); } catch { }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Announces the error-backfill block on the session timeline BEFORE the replayed
+        /// errors, so pre-agent Error events are readable as history rather than a live
+        /// failure. The web timeline additionally badges each replayed event via its
+        /// backfilled=true payload marker; this summary carries backfillSummary=true instead —
+        /// it is a live emission, not a replayed record.
+        /// </summary>
+        internal void EmitErrorBackfillSummary(int replayedCount, int droppedOverCap)
+        {
+            var message = $"[Autopilot] Replaying {replayedCount} error event(s) recorded in the Autopilot event log " +
+                $"before the agent started (lookback {ErrorBackfillLookbackMinutes / 60}h). " +
+                "These predate monitoring — if enrollment progressed afterwards, they were already resolved by a retry.";
+            if (droppedOverCap > 0)
+            {
+                message += $" {droppedOverCap} older record(s) beyond the {ErrorBackfillMaxRecords}-record cap were not replayed.";
+            }
+
+            _post.Emit(new EnrollmentEvent
+            {
+                SessionId = _sessionId,
+                TenantId = _tenantId,
+                EventType = Constants.EventTypes.ModernDeploymentLog,
+                Severity = EventSeverity.Info,
+                Source = "ModernDeploymentWatcher",
+                Phase = EnrollmentPhase.Unknown,
+                Message = message,
+                Data = new Dictionary<string, object>
+                {
+                    { "backfillSummary", true },
+                    { "replayedCount", replayedCount },
+                    { "droppedOverCap", droppedOverCap },
+                    { "lookbackMinutes", ErrorBackfillLookbackMinutes }
+                }
+            });
         }
 
         /// <summary>

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

@@ -218,15 +218,18 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Runtime
         /// This method is non-fatal: all exceptions are caught and logged.
         /// </summary>
         /// <param name="enrollmentSucceeded">
-        /// True for a successful enrollment (affects OnFailure mode check and sessioninfo.txt content).
-        /// Pass true for WhiteGlove pre-provisioning (it succeeded up to this point).
+        /// True for a successful enrollment, false for a failed one (drives the OnFailure mode
+        /// check and sessioninfo.txt content). Pass true for WhiteGlove pre-provisioning (it
+        /// succeeded up to this point). Pass <b>null</b> when the session has no outcome yet
+        /// (on-demand server-requested collection mid-enrollment): the OnFailure gate does not
+        /// apply — there is no success to skip on — and sessioninfo.txt records "In Progress".
         /// </param>
         /// <param name="fileNameSuffix">
         /// Optional suffix inserted before the .zip extension.
         /// Example: "preprov" → AgentDiagnostics-{sessionId}-{timestamp}-preprov.zip
         /// Null (default) → AgentDiagnostics-{sessionId}-{timestamp}.zip
         /// </param>
-        public virtual async Task<DiagnosticsUploadResult> CreateAndUploadAsync(bool enrollmentSucceeded, string fileNameSuffix = null)
+        public virtual async Task<DiagnosticsUploadResult> CreateAndUploadAsync(bool? enrollmentSucceeded, string fileNameSuffix = null)
         {
             try
             {
@@ -244,13 +247,15 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Runtime
                     return null;
                 }
 
-                if (string.Equals(mode, "OnFailure", StringComparison.OrdinalIgnoreCase) && enrollmentSucceeded)
+                // Null outcome (on-demand mid-session) passes through: the OnFailure gate only
+                // skips a KNOWN success — an in-flight session has nothing to skip on.
+                if (string.Equals(mode, "OnFailure", StringComparison.OrdinalIgnoreCase) && enrollmentSucceeded == true)
                 {
                     _logger.Info("Diagnostics upload skipped: enrollment succeeded and mode=OnFailure");
                     return null;
                 }
 
-                _logger.Info($"Creating diagnostics package (mode={mode}, enrollmentSucceeded={enrollmentSucceeded}{(fileNameSuffix != null ? $", suffix={fileNameSuffix}" : "")})...");
+                _logger.Info($"Creating diagnostics package (mode={mode}, enrollmentSucceeded={(enrollmentSucceeded.HasValue ? enrollmentSucceeded.ToString() : "n/a")}{(fileNameSuffix != null ? $", suffix={fileNameSuffix}" : "")})...");
 
                 // Build ZIP in memory
                 var timestamp = DateTime.UtcNow.ToString("yyyyMMddHHmmss");
@@ -343,7 +348,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Runtime
 
         // Builds the diagnostics ZIP body in-memory. Extracted from CreateAndUploadAsync so
         // tests can assert archive contents without going through the upload path.
-        internal virtual byte[] BuildArchiveBytes(bool enrollmentSucceeded)
+        internal virtual byte[] BuildArchiveBytes(bool? enrollmentSucceeded)
         {
             var tracker = new BudgetTracker(Budget);
             using (var ms = new MemoryStream())
@@ -414,14 +419,14 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Runtime
             }
         }
 
-        private void AddSessionInfo(ZipArchive archive, bool enrollmentSucceeded)
+        private void AddSessionInfo(ZipArchive archive, bool? enrollmentSucceeded)
         {
             var sb = new StringBuilder();
             sb.AppendLine($"Session ID: {_configuration.SessionId}");
             sb.AppendLine($"Tenant ID: {_configuration.TenantId}");
             sb.AppendLine($"Device Name: {Environment.MachineName}");
             sb.AppendLine($"Timestamp: {DateTime.UtcNow:O}");
-            sb.AppendLine($"Enrollment Result: {(enrollmentSucceeded ? "Succeeded" : "Failed")}");
+            sb.AppendLine($"Enrollment Result: {(enrollmentSucceeded == null ? "In Progress" : enrollmentSucceeded.Value ? "Succeeded" : "Failed")}");
 
             // Hardware info via existing DeviceInfoProvider (WMI)
             sb.AppendLine($"Manufacturer: {DeviceInfoProvider.GetManufacturer()}");

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Gather/Collectors/LogParserCollector.cs

@@ -25,14 +25,21 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
         {
             var filePath = rule.Target;
             if (string.IsNullOrEmpty(filePath))
+            {
+                context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageLogParser, "empty target — nothing to parse");
                 return null;
+            }
 
             // Expand custom tokens (%LOGGED_ON_USER_PROFILE%) and standard environment variables
             var userProfilePath = UserProfileResolver.ContainsUserProfileToken(filePath)
                 ? UserProfileResolver.GetLoggedOnUserProfilePath() : null;
             filePath = UserProfileResolver.ExpandCustomTokens(filePath);
             if (filePath == null)
+            {
+                context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageLogParser,
+                    "target contains %LOGGED_ON_USER_PROFILE% but no user is logged on — skipped this run");
                 return null; // Token present but no user logged on — skip silently
+            }
 
             // Apply IME log path override if set. The override comes from the local
             // --ime-log-path flag only (never from remote config), so the operator
@@ -66,6 +73,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
                 string.IsNullOrEmpty(patternStr))
             {
                 context.Logger.Warning($"LogParser rule {rule.RuleId} has no 'pattern' parameter");
+                context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageError,
+                    "missing 'pattern' parameter — rule can never match");
                 return null;
             }
 
@@ -93,6 +102,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
             catch (Exception ex)
             {
                 context.Logger.Warning($"LogParser rule {rule.RuleId} has invalid regex: {ex.Message}");
+                context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageError,
+                    $"invalid regex pattern — rule can never match: {ex.Message}");
                 return null;
             }
 
@@ -101,6 +112,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
             if (resolvedPaths.Count == 0)
             {
                 context.Logger.Debug($"LogParser rule {rule.RuleId}: no files found for: {filePath}");
+                context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageLogParser,
+                    $"no files matched target {filePath}" + (HasWildcard(Path.GetFileName(filePath)) ? " (wildcard)" : "") + " — nothing to parse");
                 return null;
             }
 
@@ -144,7 +157,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
             try
             {
                 // Return matched files sorted by last write time (newest first), capped at 20
-                return Directory.GetFiles(directory, fileNamePart)
+                var allMatches = Directory.GetFiles(directory, fileNamePart);
+                if (allMatches.Length > 20)
+                    context.DebugLog(ruleId, GatherRuleDebugLog.StageLogParser,
+                        $"wildcard matched {allMatches.Length} files — capped to the 20 newest");
+                return allMatches
                     .OrderByDescending(f => new FileInfo(f).LastWriteTimeUtc)
                     .Take(20)
                     .ToList();
@@ -152,6 +169,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
             catch (Exception ex)
             {
                 context.Logger.Warning($"LogParser rule {ruleId}: wildcard expansion failed for {filePath}: {ex.Message}");
+                context.DebugLog(ruleId, GatherRuleDebugLog.StageError, $"wildcard expansion failed for {filePath}: {ex.Message}");
                 return new List<string>();
             }
         }
@@ -168,10 +186,16 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
 
                 // Nothing new to read
                 if (startPosition >= fileInfo.Length)
+                {
+                    context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageLogParser,
+                        $"{Path.GetFileName(filePath)}: no new content (position {startPosition} >= length {fileInfo.Length}) — trackPosition=true, nothing re-read");
                     return;
+                }
 
                 int matchCount = 0;
                 int linesRead = 0;
+                int parseFailCount = 0;
+                int timeoutCount = 0;
                 long endPosition = startPosition;
 
                 using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
@@ -195,6 +219,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
                                 }
                                 catch (RegexMatchTimeoutException)
                                 {
+                                    timeoutCount++;
                                     continue;
                                 }
                                 if (!match.Success)
@@ -239,7 +264,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
                                 // CMTrace mode: parse line as CMTrace format, match regex against message
                                 CmTraceLogEntry entry;
                                 if (!CmTraceLogParser.TryParseLine(line, out entry))
+                                {
+                                    parseFailCount++;
                                     continue;
+                                }
 
                                 Match match;
                                 try
@@ -248,6 +276,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
                                 }
                                 catch (RegexMatchTimeoutException)
                                 {
+                                    timeoutCount++;
                                     continue;
                                 }
                                 if (!match.Success)
@@ -301,10 +330,24 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
 
                 if (matchCount > 0)
                     context.Logger.Debug($"LogParser rule {rule.RuleId}: {matchCount} matches from {linesRead} lines in {Path.GetFileName(filePath)}");
+
+                // Per-file outcome — always written so a "matched 0" run is visible too.
+                context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageLogParser,
+                    $"{Path.GetFileName(filePath)}: read {linesRead} lines from position {startPosition}->{endPosition}, " +
+                    $"matched {matchCount}, parseFailures={parseFailCount}, regexTimeouts={timeoutCount}, mode={(isTextMode ? "text" : "cmtrace")}");
+
+                if (!isTextMode && linesRead > 0 && parseFailCount == linesRead)
+                    context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageLogParser,
+                        "every line failed CMTrace parsing — if this is a plain-text log, set parameter format=text");
+
+                if (linesRead == maxLines)
+                    context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageLogParser,
+                        $"stopped at maxLines={maxLines} — remaining content is deferred to the next run");
             }
             catch (Exception ex)
             {
                 context.Logger.Warning($"LogParser rule {rule.RuleId} failed reading {filePath}: {ex.Message}");
+                context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageError, $"failed reading {filePath}: {ex}");
             }
         }
 

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Gather/Collectors/RegistryCollector.cs

@@ -113,7 +113,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather.Collectors
 
                         // Suppress the "not found" event when the rule only wants a positive signal.
                         if (emitOnlyIfExists)
+                        {
+                            context.DebugLog(rule.RuleId, GatherRuleDebugLog.StageCollector,
+                                $"registry key/value not found: {path} — emitOnlyIfExists=true, empty result");
                             return new Dictionary<string, object>(); // empty → executor emits nothing
+                        }
 
                         data["exists"] = false;
                         data["path"] = path;

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Gather/GatherRuleContext.cs

@@ -22,13 +22,20 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
         public LogFilePositionTracker FilePositionTracker { get; }
         public bool UnrestrictedMode { get; set; }
 
+        /// <summary>
+        /// Optional gather-rule debug trace writer (EnableGatherRuleDebugLog). Null when
+        /// tracing is disabled — use <see cref="DebugLog"/> for null-safe writes.
+        /// </summary>
+        public GatherRuleDebugLog DebugWriter { get; }
+
         public GatherRuleContext(
             AgentLogger logger,
             string sessionId,
             string tenantId,
             Action<EnrollmentEvent> onEventCollected,
             string imeLogPathOverride,
-            LogFilePositionTracker filePositionTracker)
+            LogFilePositionTracker filePositionTracker,
+            GatherRuleDebugLog debugLog = null)
         {
             Logger = logger ?? throw new ArgumentNullException(nameof(logger));
             SessionId = sessionId ?? throw new ArgumentNullException(nameof(sessionId));
@@ -36,8 +43,14 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
             OnEventCollected = onEventCollected ?? throw new ArgumentNullException(nameof(onEventCollected));
             ImeLogPathOverride = imeLogPathOverride;
             FilePositionTracker = filePositionTracker ?? throw new ArgumentNullException(nameof(filePositionTracker));
+            DebugWriter = debugLog;
         }
 
+        /// <summary>
+        /// Null-safe write to the gather-rule debug trace. No-op when tracing is disabled.
+        /// </summary>
+        public void DebugLog(string ruleId, string stage, string message) => DebugWriter?.Write(ruleId, stage, message);
+
         /// <summary>
         /// Emits a security_warning event and returns an empty result dictionary.
         /// Called when a gather rule targets a path/query not on the allowlist.
@@ -45,6 +58,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
         public Dictionary<string, object> EmitSecurityWarning(GatherRule rule, string collectorType, string target)
         {
             Logger.Warning($"SECURITY: {collectorType} path blocked by guard: {target} (Rule: {rule.RuleId})");
+            DebugLog(rule.RuleId, GatherRuleDebugLog.StageGuard,
+                $"{collectorType} target blocked by allowlist guard: {target} — security_warning emitted, rule produced no data");
 
             var data = new Dictionary<string, object>
             {

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Gather/GatherRuleDebugLog.cs

@@ -0,0 +1,115 @@
+using System;
+using System.IO;
+using AutopilotMonitor.Agent.V2.Core.Logging;
+
+namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
+{
+    /// <summary>
+    /// Append-only trace file for gather-rule evaluation, enabled per tenant via
+    /// EnableGatherRuleDebugLog (or --gather-debug-log). Explains every evaluation
+    /// decision — including the outcomes that produce no event — so customers can
+    /// diagnose rules that never show up in the timeline. Every write failure is
+    /// swallowed: tracing must never break gathering.
+    /// </summary>
+    public sealed class GatherRuleDebugLog
+    {
+        public const string StageConfig = "config";
+        public const string StageTrigger = "trigger";
+        public const string StageScope = "scope";
+        public const string StageExec = "exec";
+        public const string StageCollector = "collector";
+        public const string StageGuard = "guard";
+        public const string StageEmit = "emit";
+        public const string StageSuppress = "suppress";
+        public const string StageLogParser = "logparser";
+        public const string StageError = "error";
+
+        private const long DefaultMaxBytes = 10 * 1024 * 1024;
+
+        private readonly string _path;
+        private readonly long _maxBytes;
+        private readonly Action<string> _echo;
+        private readonly object _lock = new object();
+        private bool _headerWritten;
+
+        public GatherRuleDebugLog(string path, AgentLogger logger, Action<string> echo = null, long maxBytes = DefaultMaxBytes)
+        {
+            if (string.IsNullOrEmpty(path)) throw new ArgumentNullException(nameof(path));
+            _path = path;
+            _maxBytes = maxBytes;
+            _echo = echo;
+            logger?.Info($"GatherRuleDebugLog: enabled -> {path}");
+        }
+
+        /// <summary>
+        /// Writes one trace line: <c>{utc} | {ruleId} | {stage} | {message}</c>.
+        /// Newlines in <paramref name="message"/> are flattened except for the error
+        /// stage, where exception stack traces stay multi-line.
+        /// </summary>
+        public void Write(string ruleId, string stage, string message)
+        {
+            try
+            {
+                if (stage != StageError && message != null && message.IndexOf('\n') >= 0)
+                    message = message.Replace("\r", "").Replace('\n', ' ');
+
+                var line = $"{DateTime.UtcNow:yyyy-MM-ddTHH:mm:ss.fffZ} | {ruleId ?? "-"} | {stage} | {message}";
+
+                lock (_lock)
+                {
+                    EnsureFileReadyLocked();
+                    File.AppendAllText(_path, line + Environment.NewLine);
+                }
+
+                _echo?.Invoke(line);
+            }
+            catch { }
+        }
+
+        /// <summary>
+        /// One-shot helper for callers that have no executor (e.g. the flag is on but the
+        /// backend delivered zero gather rules) — the customer's trace file should explain
+        /// that too instead of silently not existing.
+        /// </summary>
+        public static void WriteStandalone(string path, string message, AgentLogger logger)
+        {
+            if (string.IsNullOrEmpty(path)) return;
+            try
+            {
+                new GatherRuleDebugLog(path, logger).Write(null, StageConfig, message);
+            }
+            catch { }
+        }
+
+        // Lazy on first write: create the directory and emit a header line. Before every
+        // append, rotate when the file exceeds maxBytes — keeping exactly one .old
+        // generation (worst case ~2x maxBytes on disk).
+        private void EnsureFileReadyLocked()
+        {
+            if (!_headerWritten)
+            {
+                var dir = Path.GetDirectoryName(_path);
+                if (!string.IsNullOrEmpty(dir))
+                    Directory.CreateDirectory(dir);
+            }
+
+            var info = new FileInfo(_path);
+            if (info.Exists && info.Length > _maxBytes)
+            {
+                var oldPath = Path.ChangeExtension(_path, null) + ".old.log";
+                if (File.Exists(oldPath))
+                    File.Delete(oldPath);
+                File.Move(_path, oldPath);
+                File.AppendAllText(_path,
+                    $"{DateTime.UtcNow:yyyy-MM-ddTHH:mm:ss.fffZ} | - | {StageConfig} | -- rotated (previous file exceeded {_maxBytes} bytes) --" + Environment.NewLine);
+            }
+
+            if (!_headerWritten)
+            {
+                File.AppendAllText(_path,
+                    $"{DateTime.UtcNow:yyyy-MM-ddTHH:mm:ss.fffZ} | - | {StageConfig} | -- gather rule debug log started --" + Environment.NewLine);
+                _headerWritten = true;
+            }
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Gather/GatherRuleExecutor.cs

@@ -22,6 +22,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
     public class GatherRuleExecutor : IDisposable
     {
         private readonly AgentLogger _logger;
+        private readonly GatherRuleDebugLog _debug;   // null unless EnableGatherRuleDebugLog / --gather-debug-log
         private readonly GatherRuleContext _context;
         private readonly Dictionary<string, IGatherRuleCollector> _collectors;
 
@@ -61,7 +62,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
         }
 
         public GatherRuleExecutor(string sessionId, string tenantId, Action<EnrollmentEvent> onEventCollected,
-            AgentLogger logger, string imeLogPathOverride = null)
+            AgentLogger logger, string imeLogPathOverride = null, string debugLogPath = null,
+            Action<string> debugEcho = null)
         {
             if (sessionId == null) throw new ArgumentNullException(nameof(sessionId));
             if (tenantId == null) throw new ArgumentNullException(nameof(tenantId));
@@ -69,9 +71,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
             if (logger == null) throw new ArgumentNullException(nameof(logger));
 
             _logger = logger;
+            _debug = string.IsNullOrEmpty(debugLogPath) ? null : new GatherRuleDebugLog(debugLogPath, logger, debugEcho);
 
             var filePositionTracker = new LogFilePositionTracker();
-            _context = new GatherRuleContext(logger, sessionId, tenantId, onEventCollected, imeLogPathOverride, filePositionTracker);
+            _context = new GatherRuleContext(logger, sessionId, tenantId, onEventCollected, imeLogPathOverride, filePositionTracker, _debug);
 
             // Register all collector strategies
             var collectorList = new IGatherRuleCollector[]
@@ -96,6 +99,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
             _collectors["command"] = _collectors["command_allowlisted"];
         }
 
+        /// <summary>
+        /// Null-safe write to the gather-rule debug trace. Never call while holding
+        /// <see cref="_scopeLock"/> — capture the message under the lock, write after release.
+        /// </summary>
+        private void DebugLog(string ruleId, string stage, string message) => _debug?.Write(ruleId, stage, message);
+
         /// <summary>
         /// Updates the active rules and starts/stops execution accordingly
         /// </summary>
@@ -111,11 +120,43 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
 
             _activeRules = rules.Where(r => r.Enabled).ToList();
 
+            // Registration summary for the debug trace: one line per delivered rule so the
+            // customer can see exactly what the agent received and how it will be triggered.
+            if (_debug != null)
+            {
+                foreach (var rule in rules)
+                {
+                    if (!rule.Enabled)
+                    {
+                        DebugLog(rule.RuleId, GatherRuleDebugLog.StageConfig, "rule disabled — will never run");
+                        continue;
+                    }
+
+                    var scope = rule.ActivePhases != null && rule.ActivePhases.Count > 0
+                        ? $"activePhases=[{string.Join(",", rule.ActivePhases)}]"
+                        : !string.IsNullOrEmpty(rule.ActiveFromPhase)
+                            ? $"activeFromPhase={rule.ActiveFromPhase}"
+                            : "unscoped";
+                    DebugLog(rule.RuleId, GatherRuleDebugLog.StageConfig,
+                        $"registered: trigger={rule.Trigger}" +
+                        (string.IsNullOrEmpty(rule.TriggerPhase) ? "" : $" triggerPhase={rule.TriggerPhase}") +
+                        (string.IsNullOrEmpty(rule.TriggerEventType) ? "" : $" triggerEventType={rule.TriggerEventType}") +
+                        $", collector={rule.CollectorType}, target={rule.Target}, {scope}" +
+                        $", emitMode={(string.IsNullOrEmpty(rule.EmitMode) ? "always" : rule.EmitMode)}" +
+                        (rule.IntervalSeconds.HasValue ? $", interval={rule.IntervalSeconds}s" : ""));
+
+                    if (rule.Trigger == "interval" && !rule.IntervalSeconds.HasValue)
+                        DebugLog(rule.RuleId, GatherRuleDebugLog.StageError,
+                            "trigger=interval but intervalSeconds is missing — rule will NEVER run");
+                }
+            }
+
             // Execute startup rules — track completion via CountdownEvent so callers can wait.
             // Scoped startup rules that are not yet in scope are deferred: they run once from
             // OnPhaseChanged when their scope activates (same _startupRulesExecuted dedup — a
             // rule runs either here or there, never both). Unscoped rules behave as before.
             List<GatherRule> pendingStartup;
+            var deferredTraces = _debug != null ? new List<KeyValuePair<string, string>>() : null;
             lock (_scopeLock)
             {
                 // A config refresh may deliver new from-phase rules after their phase was
@@ -124,7 +165,15 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
 
                 pendingStartup = _activeRules
                     .Where(r => r.Trigger == "startup" && !_startupRulesExecuted.Contains(r.RuleId))
-                    .Where(r => IsRuleInScopeLocked(r))
+                    .Where(r =>
+                    {
+                        string reason;
+                        var inScope = IsRuleInScopeLocked(r, out reason);
+                        if (!inScope && deferredTraces != null)
+                            deferredTraces.Add(new KeyValuePair<string, string>(r.RuleId,
+                                $"startup rule deferred — {reason}; runs once when its scope activates"));
+                        return inScope;
+                    })
                     .ToList();
 
                 foreach (var rule in pendingStartup)
@@ -133,6 +182,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                 }
             }
 
+            if (deferredTraces != null)
+            {
+                foreach (var trace in deferredTraces)
+                    DebugLog(trace.Key, GatherRuleDebugLog.StageScope, trace.Value);
+            }
+
             if (pendingStartup.Count > 0)
             {
                 _startupRulesLatch?.Dispose();
@@ -158,8 +213,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                 var timer = new Timer(
                     _ =>
                     {
-                        if (!IsRuleInScope(intervalRule))
+                        string skipReason;
+                        if (!IsRuleInScope(intervalRule, out skipReason))
+                        {
+                            DebugLog(intervalRule.RuleId, GatherRuleDebugLog.StageScope, $"interval tick skipped: {skipReason}");
                             return;
+                        }
                         ExecuteRule(intervalRule);
                     },
                     null,
@@ -168,6 +227,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                 );
                 _intervalTimers[intervalRule.RuleId] = timer;
                 _logger.Info($"  Interval rule {intervalRule.RuleId} scheduled every {intervalRule.IntervalSeconds}s");
+                DebugLog(intervalRule.RuleId, GatherRuleDebugLog.StageTrigger,
+                    $"interval timer scheduled every {intervalRule.IntervalSeconds}s (first run after one full interval — no immediate execution)");
             }
 
             _logger.Info($"GatherRuleExecutor: {_activeRules.Count(r => r.Trigger == "startup")} startup, " +
@@ -187,6 +248,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
             // _currentPhase moves below. A transition INTO Failed still fires the exit rules of the
             // phase that failed — that snapshot is the whole point at a failure boundary.
             List<GatherRule> exitRules = null;
+            var exitTraces = _debug != null ? new List<KeyValuePair<string, string>>() : null;
             lock (_scopeLock)
             {
                 var previousPhase = _currentPhase;
@@ -204,12 +266,22 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
 
                         // Scope gate before the dedup add — an out-of-scope pass must not consume
                         // the once-per-(rule, phase) slot. IsRuleInScopeLocked still sees the old phase.
-                        if (!IsRuleInScopeLocked(rule)) continue;
+                        string scopeReason;
+                        if (!IsRuleInScopeLocked(rule, out scopeReason))
+                        {
+                            if (exitTraces != null)
+                                exitTraces.Add(new KeyValuePair<string, string>(rule.RuleId,
+                                    $"phase_exit of {previousPhaseName} skipped: {scopeReason}"));
+                            continue;
+                        }
 
                         // "exit:" prefix keeps this key space disjoint from the phase_change keys.
                         if (!_phaseRulesExecuted.Add($"exit:{rule.RuleId}|{previousPhaseName}"))
                         {
                             _logger.Debug($"Phase-exit rule {rule.RuleId} already executed for exit of {previousPhaseName}, skipping");
+                            if (exitTraces != null)
+                                exitTraces.Add(new KeyValuePair<string, string>(rule.RuleId,
+                                    $"phase_exit already executed for exit of {previousPhaseName} — once per (rule, phase)"));
                             continue;
                         }
 
@@ -219,6 +291,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                 }
             }
 
+            if (exitTraces != null)
+            {
+                foreach (var trace in exitTraces)
+                    DebugLog(trace.Key, GatherRuleDebugLog.StageScope, trace.Value);
+            }
+
             if (exitRules != null)
             {
                 foreach (var rule in exitRules)
@@ -252,6 +330,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
             {
                 var deferredRule = rule;
                 _logger.Info($"Phase {phaseName} activated deferred startup rule {deferredRule.RuleId}");
+                DebugLog(deferredRule.RuleId, GatherRuleDebugLog.StageTrigger,
+                    $"phase {phaseName} activated deferred startup rule");
                 ThreadPool.QueueUserWorkItem(_ => ExecuteRule(deferredRule));
             }
 
@@ -262,18 +342,26 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                 {
                     // Scope gate BEFORE the dedup add — an out-of-scope pass must not consume
                     // the once-per-(rule, phase) execution slot.
-                    if (!IsRuleInScope(rule))
+                    string scopeReason;
+                    if (!IsRuleInScope(rule, out scopeReason))
+                    {
+                        DebugLog(rule.RuleId, GatherRuleDebugLog.StageScope,
+                            $"phase_change to {phaseName} skipped: {scopeReason}");
                         continue;
+                    }
 
                     // Deduplicate: only fire once per (ruleId, phase) combination
                     var deduplicationKey = $"{rule.RuleId}|{phaseName}";
                     if (!_phaseRulesExecuted.Add(deduplicationKey))
                     {
                         _logger.Debug($"Phase rule {rule.RuleId} already executed for phase {phaseName}, skipping");
+                        DebugLog(rule.RuleId, GatherRuleDebugLog.StageTrigger,
+                            $"phase_change already executed for phase {phaseName} — once per (rule, phase)");
                         continue;
                     }
 
                     _logger.Info($"Phase change triggered rule {rule.RuleId} (phase: {phaseName})");
+                    DebugLog(rule.RuleId, GatherRuleDebugLog.StageTrigger, $"phase_change to {phaseName} fired");
                     ThreadPool.QueueUserWorkItem(_ => ExecuteRule(rule));
                 }
             }
@@ -288,10 +376,16 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
             {
                 if (string.Equals(rule.TriggerEventType, eventType, StringComparison.OrdinalIgnoreCase))
                 {
-                    if (!IsRuleInScope(rule))
+                    string scopeReason;
+                    if (!IsRuleInScope(rule, out scopeReason))
+                    {
+                        DebugLog(rule.RuleId, GatherRuleDebugLog.StageScope,
+                            $"on_event {eventType} skipped: {scopeReason}");
                         continue;
+                    }
 
                     _logger.Info($"Event triggered rule {rule.RuleId} (event: {eventType})");
+                    DebugLog(rule.RuleId, GatherRuleDebugLog.StageTrigger, $"on_event {eventType} fired");
                     ThreadPool.QueueUserWorkItem(_ => ExecuteRule(rule));
                 }
             }
@@ -302,6 +396,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
             try
             {
                 _logger.Info($"Executing gather rule: {rule.RuleId} ({rule.Title})");
+                DebugLog(rule.RuleId, GatherRuleDebugLog.StageExec, $"executing: collector={rule.CollectorType}, target={rule.Target}");
 
                 var collectorType = rule.CollectorType?.ToLower();
 
@@ -309,6 +404,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                 if (collectorType == null || !_collectors.TryGetValue(collectorType, out collector))
                 {
                     _logger.Warning($"Unknown collector type: {rule.CollectorType} for rule {rule.RuleId}");
+                    DebugLog(rule.RuleId, GatherRuleDebugLog.StageError, $"unknown collector type '{rule.CollectorType}' — nothing emitted");
                     return;
                 }
 
@@ -316,7 +412,19 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
 
                 // LogParser (and potentially others) emit events directly and return null
                 if (result == null)
+                {
+                    DebugLog(rule.RuleId, GatherRuleDebugLog.StageCollector,
+                        collectorType == "logparser"
+                            ? "logparser emits per-match events directly — see logparser lines above for the per-file outcome"
+                            : "collector returned null — nothing emitted");
                     return;
+                }
+
+                if (result.Count == 0)
+                {
+                    DebugLog(rule.RuleId, GatherRuleDebugLog.StageCollector,
+                        "collector returned EMPTY result — nothing emitted (typical causes: target not found with emitOnlyIfExists, or guard block — see guard line if present)");
+                }
 
                 if (result.Count > 0)
                 {
@@ -325,8 +433,19 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                     // empty result never reaches this point, so an emitOnlyIfExists miss neither
                     // emits nor updates the hash — composing to "one event on appearance, then
                     // only on change".
-                    if (IsOnChangeMode(rule) && !ShouldEmitOnChange(rule, result))
-                        return;
+                    if (IsOnChangeMode(rule))
+                    {
+                        string hashPrefix;
+                        int suppressedStreak;
+                        if (!ShouldEmitOnChange(rule, result, out hashPrefix, out suppressedStreak))
+                        {
+                            DebugLog(rule.RuleId, GatherRuleDebugLog.StageSuppress,
+                                $"result unchanged (hash {hashPrefix}) — emit suppressed (on_change), suppressed streak={suppressedStreak}");
+                            return;
+                        }
+                        DebugLog(rule.RuleId, GatherRuleDebugLog.StageEmit,
+                            $"result changed (hash {hashPrefix})" + (suppressedStreak > 0 ? $" after {suppressedStreak} suppressed polls" : ""));
+                    }
 
                     result["ruleId"] = rule.RuleId;
                     result["ruleTitle"] = rule.Title;
@@ -357,11 +476,15 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                         Message = $"Gather: {rule.Title}",
                         Data = result
                     });
+                    DebugLog(rule.RuleId, GatherRuleDebugLog.StageEmit,
+                        $"emitted {eventType} (severity={severity}, {result.Count} fields)");
                 }
             }
             catch (Exception ex)
             {
                 _logger.Warning($"Gather rule {rule.RuleId} failed: {ex.Message}");
+                // Full exception incl. stack trace only in the debug trace — the agent log stays terse.
+                DebugLog(rule.RuleId, GatherRuleDebugLog.StageError, $"rule execution failed: {ex}");
             }
         }
 
@@ -375,15 +498,33 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
 
         // Internal so the scope matrix is testable synchronously (no timer/ThreadPool races).
         internal bool IsRuleInScope(GatherRule rule)
+        {
+            string reason;
+            return IsRuleInScope(rule, out reason);
+        }
+
+        /// <summary>
+        /// Scope gate with a human-readable skip reason for the debug trace. The reason is
+        /// captured under the lock but must be WRITTEN outside it (never trace under _scopeLock).
+        /// </summary>
+        internal bool IsRuleInScope(GatherRule rule, out string reason)
         {
             lock (_scopeLock)
             {
-                return IsRuleInScopeLocked(rule);
+                return IsRuleInScopeLocked(rule, out reason);
             }
         }
 
         private bool IsRuleInScopeLocked(GatherRule rule)
         {
+            string reason;
+            return IsRuleInScopeLocked(rule, out reason);
+        }
+
+        private bool IsRuleInScopeLocked(GatherRule rule, out string reason)
+        {
+            reason = null;
+
             if (!HasPhaseScope(rule))
                 return true; // unscoped — legacy behavior
 
@@ -400,7 +541,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                 // No phase signal yet (or scope tokens that never match, e.g. "Unknown"):
                 // scoped rules stay inactive.
                 if (_currentPhase == EnrollmentPhase.Unknown)
+                {
+                    reason = "currentPhase=Unknown — scoped rules stay inactive until the first phase signal";
                     return false;
+                }
 
                 var phaseName = _currentPhase.ToString();
                 foreach (var phase in rule.ActivePhases)
@@ -408,10 +552,15 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                     if (string.Equals(phase, phaseName, StringComparison.OrdinalIgnoreCase))
                         return true;
                 }
+                reason = $"out of scope (currentPhase={phaseName}, activePhases=[{string.Join(",", rule.ActivePhases)}])";
                 return false;
             }
 
-            return _fromPhaseLatched.Contains(rule.RuleId);
+            if (_fromPhaseLatched.Contains(rule.RuleId))
+                return true;
+
+            reason = $"activeFromPhase={rule.ActiveFromPhase} not latched yet (currentPhase={_currentPhase})";
+            return false;
         }
 
         /// <summary>
@@ -457,8 +606,23 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
         /// Internal so the state machine is testable synchronously (no timer/ThreadPool races).
         /// </summary>
         internal bool ShouldEmitOnChange(GatherRule rule, Dictionary<string, object> result)
+        {
+            string hashPrefix;
+            int suppressedStreak;
+            return ShouldEmitOnChange(rule, result, out hashPrefix, out suppressedStreak);
+        }
+
+        /// <summary>
+        /// Overload exposing the hash prefix and suppression streak for the debug trace:
+        /// on suppress, <paramref name="suppressedStreak"/> is the updated streak count;
+        /// on emit, it is the streak that just ended (0 when none).
+        /// </summary>
+        internal bool ShouldEmitOnChange(GatherRule rule, Dictionary<string, object> result,
+            out string hashPrefix, out int suppressedStreak)
         {
             var hash = ComputeCanonicalHash(result);
+            hashPrefix = hash.Length > 8 ? hash.Substring(0, 8) : hash;
+            suppressedStreak = 0;
             bool emit;
             lock (_scopeLock)
             {
@@ -469,6 +633,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                     _suppressed[rule.RuleId] = _suppressed.TryGetValue(rule.RuleId, out streak)
                         ? (streak.Count + 1, streak.SinceUtc)
                         : (1, DateTime.UtcNow);
+                    suppressedStreak = _suppressed[rule.RuleId].Count;
                     emit = false;
                 }
                 else
@@ -479,6 +644,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Gather
                     {
                         result["suppressedPolls"] = streak.Count;
                         result["suppressedSinceUtc"] = streak.SinceUtc.ToString("o", CultureInfo.InvariantCulture);
+                        suppressedStreak = streak.Count;
                     }
                     _suppressed.Remove(rule.RuleId);
                     emit = true;

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

@@ -483,7 +483,16 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
                     logger: logger,
                     rules: _remoteConfig.GatherRules,
                     imeLogPathOverride: _agentConfig.ImeLogPathOverride,
-                    unrestrictedMode: _agentConfig.UnrestrictedMode));
+                    unrestrictedMode: _agentConfig.UnrestrictedMode,
+                    gatherDebugLogPath: _agentConfig.GatherRuleDebugLogPath));
+            }
+            else if (!string.IsNullOrEmpty(_agentConfig.GatherRuleDebugLogPath))
+            {
+                // Debug trace is on but the backend delivered zero gather rules — the trace
+                // file must say so instead of silently not existing.
+                Monitoring.Telemetry.Gather.GatherRuleDebugLog.WriteStandalone(
+                    _agentConfig.GatherRuleDebugLogPath,
+                    "no gather rules delivered by backend — nothing to execute", logger);
             }
 
             return new CollectorSurfaces(hosts, imeLogHost, espAndHelloHost, aadJoinHost);

src/Agent/AutopilotMonitor.Agent.V2.Core/Orchestration/Hosts/GatherRuleExecutorHost.cs

@@ -39,7 +39,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             AgentLogger logger,
             List<GatherRule> rules,
             string? imeLogPathOverride,
-            bool unrestrictedMode = false)
+            bool unrestrictedMode = false,
+            string? gatherDebugLogPath = null)
         {
             if (ingress == null) throw new ArgumentNullException(nameof(ingress));
             if (clock == null) throw new ArgumentNullException(nameof(clock));
@@ -55,9 +56,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             // session mode we wrap post.Emit so every session-mode gather event still
             // flows through the InformationalEvent ingress pipe before hitting the
             // telemetry spool — Rail-A semantics for ordering / replay determinism.
-            var post = new InformationalEventPost(ingress, clock);
+            var post = new InformationalEventPost(ingress, clock, logger);
             _executor = new Monitoring.Telemetry.Gather.GatherRuleExecutor(
-                sessionId, tenantId, evt => post.Emit(evt), logger, imeLogPathOverride);
+                sessionId, tenantId, evt => post.Emit(evt), logger, imeLogPathOverride,
+                debugLogPath: gatherDebugLogPath);
             _observableIngress = ingress as SignalIngress;
         }
 

src/Agent/AutopilotMonitor.Agent.V2.Core/Termination/EnrollmentTerminationHandler.cs

@@ -39,8 +39,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Termination
     ///     <see cref="SessionStage.WhiteGloveSealed"/> (Part-1 exit, session resumes Part 2).</item>
     ///   <item>WhiteGlove Part-1 path: stop peripheral collectors first (so their stop-time
     ///     stragglers — e.g. <c>network_bandwidth_estimate</c> — sequence BEFORE the marker),
-    ///     then emit <c>whiteglove_part1_complete</c>, drain spool, and write
-    ///     <c>whiteglove.complete</c> marker via <see cref="SessionIdPersistence.SaveWhiteGloveComplete"/>
+    ///     upload the diagnostics package as a pre-provisioning intermediate (suffix
+    ///     <c>preprov</c>, same mode gating as the terminal path — the seal counts as a
+    ///     success, so <c>OnFailure</c> skips), then emit <c>whiteglove_part1_complete</c>,
+    ///     drain spool, and write <c>whiteglove.complete</c> marker via
+    ///     <see cref="SessionIdPersistence.SaveWhiteGloveComplete"/>
     ///     so Part-2 resume is detected on the next boot.</item>
     ///   <item>Signal the caller-owned shutdown <see cref="ManualResetEventSlim"/>.</item>
     /// </list>
@@ -241,6 +244,18 @@ namespace AutopilotMonitor.Agent.V2.Core.Termination
                     // the full Stop() later is a no-op for the hosts.
                     StopPeripheralCollectorsBestEffort();
 
+                    // V1 parity (restored 2026-07-28) — upload the diagnostics package as a
+                    // pre-provisioning intermediate. Between reseal and user OOBE the device
+                    // may sit boxed for weeks, and if Part 2 never uploads (never runs, or
+                    // OnFailure + success) the Part-1 forensics would be lost to self-destruct.
+                    // No dedicated flag: the existing mode semantics apply — Always uploads,
+                    // OnFailure skips (the seal is a success; a Part-1 failure terminates via
+                    // the regular Failed path below, which uploads), Off does nothing. Must run
+                    // BEFORE the whiteglove_part1_complete emit so diagnostics_* events keep a
+                    // lower sequence than the Part-1/Part-2 boundary marker. Best-effort: a
+                    // reseal-reboot racing the upload just loses the intermediate package.
+                    RunUploadDiagnosticsWithEvents(args, suffixOverride: "preprov");
+
                     EmitEventSafe(new EnrollmentEvent
                     {
                         SessionId = _configuration.SessionId,
@@ -777,7 +792,13 @@ namespace AutopilotMonitor.Agent.V2.Core.Termination
                 StringComparison.Ordinal);
         }
 
-        private void RunUploadDiagnosticsWithEvents(EnrollmentTerminatedEventArgs args)
+        /// <param name="args">Termination payload — outcome drives the OnFailure gate.</param>
+        /// <param name="suffixOverride">
+        /// Blob-name suffix override. Null (terminal path) derives "success"/"failure" from
+        /// the outcome; the WhiteGlove Part-1 seal passes "preprov" so the intermediate
+        /// package is distinguishable from the later Part-2 terminal upload.
+        /// </param>
+        private void RunUploadDiagnosticsWithEvents(EnrollmentTerminatedEventArgs args, string suffixOverride = null)
         {
             var mode = _configuration.DiagnosticsUploadMode ?? "Off";
             if (!_configuration.DiagnosticsUploadEnabled || string.Equals(mode, "Off", StringComparison.OrdinalIgnoreCase))
@@ -813,7 +834,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Termination
             DiagnosticsUploadResult result = null;
             try
             {
-                var suffix = enrollmentSucceeded ? "success" : "failure";
+                var suffix = suffixOverride ?? (enrollmentSucceeded ? "success" : "failure");
                 result = _uploadDiagnosticsAsync(enrollmentSucceeded, suffix).GetAwaiter().GetResult();
             }
             catch (Exception ex)

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

@@ -221,8 +221,18 @@ namespace AutopilotMonitor.Agent.V2
                         },
                     });
 
-                    // Step 4 — run the executor and wait.
-                    using (var executor = new GatherRuleExecutor(sessionId, tenantId, emitEvent, logger, config.ImeLogPathOverride))
+                    // Step 4 — run the executor and wait. Diagnostic mode always writes the
+                    // gather-rule debug trace (CLI override or default path) and mirrors it
+                    // to the console in --console mode.
+                    var gatherDebugLogPath = !string.IsNullOrEmpty(config.GatherRuleDebugLogPath)
+                        ? config.GatherRuleDebugLogPath
+                        : Environment.ExpandEnvironmentVariables(Constants.GatherRuleDebugLogPath);
+                    logger.Info($"--run-gather-rules: debug trace -> {gatherDebugLogPath}");
+                    if (consoleMode) Console.WriteLine($"Debug trace: {gatherDebugLogPath}");
+
+                    using (var executor = new GatherRuleExecutor(sessionId, tenantId, emitEvent, logger, config.ImeLogPathOverride,
+                        debugLogPath: gatherDebugLogPath,
+                        debugEcho: consoleMode ? (Action<string>)(line => Console.WriteLine($"  {line}")) : null))
                     {
                         // Diagnostic mode has no enrollment phase context — scoped rules
                         // (activePhases / activeFromPhase) execute unconditionally here.

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

@@ -303,6 +303,7 @@ namespace AutopilotMonitor.Agent.V2
             var apiBaseUrl = GetArgValue(args, "--api-url", "--backend-api") ?? Constants.ApiBaseUrl;
             var imeLogPathOverride = GetArgValue(args, "--ime-log-path");
             var imeMatchLogPath = GetArgValue(args, "--ime-match-log");
+            var gatherDebugLogPath = GetArgValue(args, "--gather-debug-log");
 
             // Dev / test — IME log replay (V1 compat mode). Feeds ImeLogTracker.SimulationMode
             // + SpeedFactor so recorded raw IME logs are replayed at an accelerated rate; signal
@@ -373,6 +374,7 @@ namespace AutopilotMonitor.Agent.V2
                 EnableGeoLocation = !disableGeoLocation,
                 ImeLogPathOverride = imeLogPathOverride,
                 ImeMatchLogPath = imeMatchLogPath,
+                GatherRuleDebugLogPath = gatherDebugLogPath,
                 KeepLogFile = keepLogFile,
                 SelfDestructOnComplete = !noCleanup,
                 CommandLineArgs = FormatArgsForLog(args),
@@ -485,6 +487,7 @@ namespace AutopilotMonitor.Agent.V2
             Console.Out.WriteLine("  --api-url <URL>                   Override backend API base URL (alias: --backend-api)");
             Console.Out.WriteLine("  --ime-log-path <PATH>             Override IME logs directory");
             Console.Out.WriteLine("  --ime-match-log <PATH>            Write matched IME log lines to file (debug)");
+            Console.Out.WriteLine("  --gather-debug-log <PATH>         Write gather-rule evaluation trace to file (debug)");
             Console.Out.WriteLine();
             Console.Out.WriteLine("Dev / Test:");
             Console.Out.WriteLine("  --replay-log-dir <PATH>           Replay IME logs from this directory (simulation mode)");

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

@@ -46,8 +46,12 @@ namespace AutopilotMonitor.Agent.V2.Runtime
                     try { var _ = await remoteConfigService.FetchConfigAsync(); 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
+                // sessioninfo.txt honest ("In Progress") and passes the OnFailure gate by
+                // semantics (there is no success to skip on) instead of the former
+                // enrollmentSucceeded:false workaround that stamped in-flight packages "Failed".
                 uploadDiagnosticsAsync: async (suffix) =>
-                    await diagnosticsService.CreateAndUploadAsync(enrollmentSucceeded: false, fileNameSuffix: suffix),
+                    await diagnosticsService.CreateAndUploadAsync(enrollmentSucceeded: null, fileNameSuffix: suffix),
                 onTerminateRequested: action => OnTerminateRequested(
                     action, agentConfig, orchestrator, terminationHandler, shutdown, shutdownComplete, logger),
                 post: post);

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

@@ -0,0 +1,48 @@
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.Models;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Cover for the ConnectionType predicate used on every search path that does NOT push the
+/// filter to OData — the deviceProperties batch-get (<c>ApplyBasicFilters</c>) and the legacy
+/// unpaged scan. Sessions that predate the projection (null ConnectionType) must never match
+/// a set filter; an unset filter matches everything.
+/// </summary>
+public class ConnectionTypeFilterTests
+{
+    private static SessionSummary Session(string? connectionType) =>
+        new() { SessionId = "s", TenantId = "t", ConnectionType = connectionType };
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("WiFi")]
+    [InlineData("Ethernet")]
+    public void NoFilter_AlwaysMatches(string? connectionType)
+    {
+        var filter = new SessionSearchFilter();
+        Assert.True(TableStorageService.MatchesConnectionType(Session(connectionType), filter));
+    }
+
+    [Theory]
+    [InlineData("Ethernet", true)]
+    [InlineData("ethernet", true)]  // case-insensitive, matching the other string filters
+    [InlineData("WiFi", false)]
+    [InlineData(null, false)]       // legacy session without the projected column
+    public void EthernetFilter_MatchesOnlyEthernet(string? connectionType, bool expected)
+    {
+        var filter = new SessionSearchFilter { ConnectionType = "Ethernet" };
+        Assert.Equal(expected, TableStorageService.MatchesConnectionType(Session(connectionType), filter));
+    }
+
+    [Theory]
+    [InlineData("WiFi", true)]
+    [InlineData("Ethernet", false)]
+    [InlineData(null, false)]
+    public void WiFiFilter_MatchesOnlyWiFi(string? connectionType, bool expected)
+    {
+        var filter = new SessionSearchFilter { ConnectionType = "WiFi" };
+        Assert.Equal(expected, TableStorageService.MatchesConnectionType(Session(connectionType), filter));
+    }
+}

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

@@ -0,0 +1,124 @@
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.Models;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Pins the per-session connection-type projection (2026-07-28): the agent stamps
+/// <c>connectionType</c> ("WiFi"/"Ethernet") into every <c>network_interface_info</c>
+/// emission (initial collect + re-collect on change); ingest takes the LAST matching
+/// event of the batch and persists it via <c>UpdateSessionConnectionTypeAsync</c>
+/// (last-write-wins → a device that switches media mid-enrollment is relabeled).
+/// The no-NIC payload ({"status":"no_active_interface"}) carries no connectionType
+/// and must never match.
+/// </summary>
+public class IngestConnectionTypeProjectionTests
+{
+    private static EnrollmentEvent NicInfo(string? connectionType)
+    {
+        var evt = new EnrollmentEvent
+        {
+            EventType = "network_interface_info",
+            Data = new Dictionary<string, object>
+            {
+                ["adapterName"] = "Ethernet 2",
+                ["linkSpeedMbps"] = 1000L,
+            },
+        };
+        if (connectionType != null) evt.Data["connectionType"] = connectionType;
+        return evt;
+    }
+
+    [Fact]
+    public void EthernetEmission_IsExtracted()
+    {
+        var events = new List<EnrollmentEvent> { NicInfo("Ethernet") };
+
+        Assert.True(EventIngestProcessor.TryExtractConnectionType(events, out var type));
+        Assert.Equal("Ethernet", type);
+    }
+
+    [Fact]
+    public void LastEmissionOfBatch_Wins()
+    {
+        // Media switch mid-batch (dock removed → WiFi) — the most recent state wins.
+        var events = new List<EnrollmentEvent>
+        {
+            NicInfo("Ethernet"),
+            new EnrollmentEvent { EventType = "download_progress" },
+            NicInfo("WiFi"),
+        };
+
+        Assert.True(EventIngestProcessor.TryExtractConnectionType(events, out var type));
+        Assert.Equal("WiFi", type);
+    }
+
+    [Fact]
+    public void NoActiveInterfacePayload_DoesNotMatch()
+    {
+        // The no-NIC emission carries only {"status":"no_active_interface"}.
+        var events = new List<EnrollmentEvent>
+        {
+            new EnrollmentEvent
+            {
+                EventType = "network_interface_info",
+                Data = new Dictionary<string, object> { ["status"] = "no_active_interface" },
+            },
+        };
+
+        Assert.False(EventIngestProcessor.TryExtractConnectionType(events, out _));
+    }
+
+    [Fact]
+    public void NoActiveInterfaceAfterValidEmission_DoesNotShadowIt()
+    {
+        // The predicate selects the last event that CARRIES connectionType.
+        var events = new List<EnrollmentEvent>
+        {
+            NicInfo("WiFi"),
+            new EnrollmentEvent
+            {
+                EventType = "network_interface_info",
+                Data = new Dictionary<string, object> { ["status"] = "no_active_interface" },
+            },
+        };
+
+        Assert.True(EventIngestProcessor.TryExtractConnectionType(events, out var type));
+        Assert.Equal("WiFi", type);
+    }
+
+    [Theory]
+    [InlineData("Cellular")]
+    [InlineData("wifi")]      // agent emits exact casing — anything else is unexpected
+    [InlineData("")]
+    public void UnexpectedValues_AreDroppedDefensively(string raw)
+    {
+        var events = new List<EnrollmentEvent> { NicInfo(raw) };
+
+        Assert.False(EventIngestProcessor.TryExtractConnectionType(events, out _));
+    }
+
+    [Fact]
+    public void BatchWithoutNicEvents_DoesNotMatch()
+    {
+        var events = new List<EnrollmentEvent>
+        {
+            new EnrollmentEvent { EventType = "esp_phase_changed" },
+            new EnrollmentEvent { EventType = "agent_metrics_snapshot" },
+        };
+
+        Assert.False(EventIngestProcessor.TryExtractConnectionType(events, out _));
+    }
+
+    [Fact]
+    public void NullData_DoesNotMatch()
+    {
+        var events = new List<EnrollmentEvent>
+        {
+            new EnrollmentEvent { EventType = "network_interface_info", Data = null! },
+        };
+
+        Assert.False(EventIngestProcessor.TryExtractConnectionType(events, out _));
+    }
+}

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

@@ -45,6 +45,12 @@ public class SessionIndexProjectionTests
             ["IsSelfDeployingProfile"] = true,
             // Device-validation path recorded at registration — shown on the session detail page.
             ["ValidatedBy"] = "AutopilotV1",
+            // Agent→backend HTTP latency projection (UpdateSessionNetworkLatencyAsync merges these).
+            ["AvgApiLatencyMs"] = 513.5,
+            ["ApiRequestCount"] = 100,
+            // Connection-type projection (UpdateSessionConnectionTypeAsync merges this) —
+            // search-filterable (connectionType= pushes an OData eq on the index).
+            ["ConnectionType"] = "Ethernet",
         };
 
         var idx = TableStorageService.BuildSessionIndexEntity(session, IndexRowKey, StartedAt);
@@ -67,6 +73,9 @@ public class SessionIndexProjectionTests
         Assert.True(idx.GetBoolean("ExcessiveEventsAutoActioned"));
         Assert.True(idx.GetBoolean("IsSelfDeployingProfile"));
         Assert.Equal("AutopilotV1", idx.GetString("ValidatedBy"));
+        Assert.Equal(513.5, idx.GetDouble("AvgApiLatencyMs"));
+        Assert.Equal(100, idx.GetInt32("ApiRequestCount"));
+        Assert.Equal("Ethernet", idx.GetString("ConnectionType"));
     }
 
     [Fact]
@@ -86,6 +95,8 @@ public class SessionIndexProjectionTests
         Assert.False(idx.ContainsKey("FailureSource"));
         Assert.False(idx.ContainsKey("StalledAt"));
         Assert.False(idx.ContainsKey("ValidatedBy"));
+        Assert.False(idx.ContainsKey("AvgApiLatencyMs"));
+        Assert.False(idx.ContainsKey("ConnectionType"));
         // Always-present counts/flags mirror the Sessions defaults.
         Assert.Equal(0, idx.GetInt32("PlatformScriptCount"));
         Assert.Equal(0, idx.GetInt32("RemediationScriptCount"));

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

@@ -40,6 +40,7 @@ public class StoreSessionReregistrationPreserveTests
             ["PlatformScriptCount"]    = 3,
             ["RemediationScriptCount"] = 5,
             ["RebootCount"]            = 7,
+            ["ConnectionType"]         = "Ethernet",
         };
         existing.ETag = new ETag("0xEXISTING");
 
@@ -71,6 +72,9 @@ public class StoreSessionReregistrationPreserveTests
         Assert.Equal(7, harness.Written.GetInt32("RebootCount"));
         // EventCount preservation is the established sibling behaviour — assert it as a sanity anchor.
         Assert.Equal(42, harness.Written.GetInt32("EventCount"));
+        // Merge-mode field (UpdateSessionConnectionTypeAsync) — must survive the Replace so the
+        // value isn't lost in the window until the restarted agent re-emits network_interface_info.
+        Assert.Equal("Ethernet", harness.Written.GetString("ConnectionType"));
     }
 
     [Fact]

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

@@ -413,6 +413,7 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
                 { "EnableTimezoneAutoSet", config.EnableTimezoneAutoSet },
                 { "NtpServer", config.NtpServer },
                 { "EnableImeMatchLog", config.EnableImeMatchLog },
+                { "EnableGatherRuleDebugLog", config.EnableGatherRuleDebugLog },
                 { "LogLevel", config.LogLevel },
                 { "MaxBatchSize", config.MaxBatchSize },
                 { "DiagnosticsBlobSasUrl", config.DiagnosticsBlobSasUrl },
@@ -514,6 +515,7 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
                 EnableTimezoneAutoSet = entity.GetBoolean("EnableTimezoneAutoSet"),
                 NtpServer = string.IsNullOrWhiteSpace(entity.GetString("NtpServer")) ? "time.windows.com" : entity.GetString("NtpServer"),
                 EnableImeMatchLog = entity.GetBoolean("EnableImeMatchLog"),
+                EnableGatherRuleDebugLog = entity.GetBoolean("EnableGatherRuleDebugLog"),
                 LogLevel = entity.GetString("LogLevel"),
                 MaxBatchSize = entity.GetInt32("MaxBatchSize"),
                 DiagnosticsBlobSasUrl = entity.GetString("DiagnosticsBlobSasUrl"),

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

@@ -152,6 +152,10 @@ namespace AutopilotMonitor.Functions.DataAccess.TableStorage
             double avgLatencyMs, int requestCount)
             => _storage.UpdateSessionNetworkLatencyAsync(tenantId, sessionId, avgLatencyMs, requestCount);
 
+        public Task UpdateSessionConnectionTypeAsync(string tenantId, string sessionId,
+            string connectionType)
+            => _storage.UpdateSessionConnectionTypeAsync(tenantId, sessionId, connectionType);
+
         public Task<List<SessionSummary>> GetSessionsWithEventCountAboveAsync(string tenantId, int threshold)
             => _storage.GetSessionsWithEventCountAboveAsync(tenantId, threshold);
 

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

@@ -270,12 +270,13 @@ namespace AutopilotMonitor.Functions.Functions.Config
             var response = req.CreateResponse(HttpStatusCode.OK);
             await response.WriteAsJsonAsync(new AgentConfigResponse
             {
-                ConfigVersion = 35, // MDM reboot-policy watcher (mdm_policy_reboot_required / esp_reboot_coalescing)
+                ConfigVersion = 36, // EnableGatherRuleDebugLog (local gather-rule evaluation trace)
                 UploadIntervalSeconds = 10,
                 SelfDestructOnComplete = tenantConfig.SelfDestructOnComplete ?? true,
                 KeepLogFile = tenantConfig.KeepLogFile ?? false,
                 EnableGeoLocation = tenantConfig.EnableGeoLocation ?? true,
                 EnableImeMatchLog = tenantConfig.EnableImeMatchLog ?? false,
+                EnableGatherRuleDebugLog = tenantConfig.EnableGatherRuleDebugLog ?? false,
                 MaxAuthFailures = tenantConfig.MaxAuthFailures ?? 5,
                 AuthFailureTimeoutMinutes = tenantConfig.AuthFailureTimeoutMinutes ?? 0,
                 LogLevel = tenantConfig.LogLevel ?? "Info",

src/Backend/AutopilotMonitor.Functions/Functions/Raw/QueryRawSessionsFunction.cs

@@ -130,6 +130,8 @@ namespace AutopilotMonitor.Functions.Functions.Raw
                 filter.IsSelfDeployingProfile = sdp;
             if (int.TryParse(query["rebootCountMin"], out var rcMin)) filter.RebootCountMin = rcMin;
             if (int.TryParse(query["rebootCountMax"], out var rcMax)) filter.RebootCountMax = rcMax;
+            var connectionType = query["connectionType"];
+            if (!string.IsNullOrEmpty(connectionType)) filter.ConnectionType = connectionType;
 
             var callerTenantId = TenantHelper.GetTenantId(req);
 

src/Backend/AutopilotMonitor.Functions/Functions/Sessions/SearchSessionsFunction.cs

@@ -140,6 +140,7 @@ public class SearchSessionsFunction
             ImeAgentVersion = query["imeAgentVersion"],
             AgentVersionPrefix = query["agentVersionPrefix"],
             ImeAgentVersionPrefix = query["imeAgentVersionPrefix"],
+            ConnectionType = query["connectionType"],
             // Limit field is a no-op in the paged path — pagination drives count.
         };
 
@@ -212,6 +213,7 @@ public class SearchSessionsFunction
             if (fields.Contains("rebootCount")) dict["rebootCount"] = s.RebootCount;
             if (fields.Contains("avgApiLatencyMs")) dict["avgApiLatencyMs"] = s.AvgApiLatencyMs;
             if (fields.Contains("apiRequestCount")) dict["apiRequestCount"] = s.ApiRequestCount;
+            if (fields.Contains("connectionType")) dict["connectionType"] = s.ConnectionType;
 
             if (dict.Count == 0)
             {

src/Backend/AutopilotMonitor.Functions/Pagination/SearchSessionsPagination.cs

@@ -53,6 +53,7 @@ namespace AutopilotMonitor.Functions.Pagination
                 new KeyValuePair<string, string?>("startedBefore", filter.StartedBefore?.ToUniversalTime().ToString("o", CultureInfo.InvariantCulture)),
                 new KeyValuePair<string, string?>("rebootCountMin", filter.RebootCountMin?.ToString(CultureInfo.InvariantCulture)),
                 new KeyValuePair<string, string?>("rebootCountMax", filter.RebootCountMax?.ToString(CultureInfo.InvariantCulture)),
+                new KeyValuePair<string, string?>("connectionType", filter.ConnectionType),
             };
             if (filter.DeviceProperties != null)
             {

src/Backend/AutopilotMonitor.Functions/Services/EventIngestProcessor.cs

@@ -151,6 +151,14 @@ namespace AutopilotMonitor.Functions.Services
                         "Fire-and-forget UpdateSessionNetworkLatencyAsync failed"), TaskContinuationOptions.OnlyOnFaulted);
             }
 
+            if (TryExtractConnectionType(request.Events, out var connectionType))
+            {
+                _ = _sessionRepo.UpdateSessionConnectionTypeAsync(
+                        request.TenantId, request.SessionId, connectionType)
+                    .ContinueWith(t => _logger.LogWarning(t.Exception?.InnerException,
+                        "Fire-and-forget UpdateSessionConnectionTypeAsync failed"), TaskContinuationOptions.OnlyOnFaulted);
+            }
+
             var classification = ClassifyEvents(storedEvents);
 
             foreach (var summary in classification.AppInstallUpdates.Values)
@@ -432,6 +440,28 @@ namespace AutopilotMonitor.Functions.Services
             return true;
         }
 
+        /// <summary>
+        /// Connection-type projection: the agent stamps connectionType ("WiFi"/"Ethernet")
+        /// into every network_interface_info emission (initial collect + re-collect), so the
+        /// LAST event of the batch carries the current media and a plain overwrite is
+        /// idempotent against replays. The no-NIC payload ({"status":"no_active_interface"})
+        /// carries no connectionType and never matches. Values outside WiFi/Ethernet are
+        /// dropped defensively. Exposed as internal for unit testing.
+        /// </summary>
+        internal static bool TryExtractConnectionType(
+            List<EnrollmentEvent> events, out string connectionType)
+        {
+            connectionType = string.Empty;
+            var nicEvent = events.LastOrDefault(e =>
+                e.EventType == Shared.Constants.EventTypes.NetworkInterfaceInfo &&
+                e.Data?.ContainsKey("connectionType") == true);
+            var raw = nicEvent?.Data?["connectionType"]?.ToString();
+            if (raw != "WiFi" && raw != "Ethernet")
+                return false;
+            connectionType = raw;
+            return true;
+        }
+
         /// <summary>
         /// Numeric reader for agent event Data values, which arrive as boxed Newtonsoft
         /// primitives (integer → long, decimal → double) — same coercion ladder as

src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.AgentApi.cs

@@ -654,6 +654,11 @@ namespace AutopilotMonitor.Functions.Services
                 parts.Add($"RebootCount ge {filter.RebootCountMin.Value}");
             if (filter.RebootCountMax.HasValue)
                 parts.Add($"RebootCount le {filter.RebootCountMax.Value}");
+            // ConnectionType exact match pushed to OData. Legacy index rows that predate
+            // the projected column lack the property and are excluded by the eq (they
+            // carry no connection data, which is the intended result).
+            if (!string.IsNullOrEmpty(filter.ConnectionType))
+                parts.Add($"ConnectionType eq '{ODataSanitizer.EscapeValue(filter.ConnectionType)}'");
             return parts.Count == 0 ? null : string.Join(" and ", parts);
         }
 
@@ -670,6 +675,19 @@ namespace AutopilotMonitor.Functions.Services
             return true;
         }
 
+        /// <summary>
+        /// Client-side ConnectionType predicate — same backstop role as
+        /// <see cref="MatchesRebootCountBounds"/>: applied on the search paths that do NOT
+        /// push the filter to OData (device-snapshot batch-get, legacy unpaged scan) and
+        /// redundantly on the OData scan paths. Sessions without the projected column
+        /// (null) never match a set filter.
+        /// </summary>
+        internal static bool MatchesConnectionType(SessionSummary session, SessionSearchFilter filter)
+        {
+            if (string.IsNullOrEmpty(filter.ConnectionType)) return true;
+            return string.Equals(session.ConnectionType, filter.ConnectionType, StringComparison.OrdinalIgnoreCase);
+        }
+
         private static bool MatchesScanClientFilters(SessionSummary session, SessionSearchFilter filter)
         {
             if (!string.IsNullOrEmpty(filter.SerialNumber) &&
@@ -683,9 +701,10 @@ namespace AutopilotMonitor.Functions.Services
                 return false;
             if (filter.StartedAfter.HasValue && session.StartedAt < filter.StartedAfter.Value) return false;
             if (filter.StartedBefore.HasValue && session.StartedAt > filter.StartedBefore.Value) return false;
-            // RebootCount is also pushed to OData in BuildSearchScanFilter; this is a defensive
-            // backstop so the bound holds even if that push-down is ever weakened.
+            // RebootCount / ConnectionType are also pushed to OData in BuildSearchScanFilter;
+            // these are defensive backstops so the bound holds even if that push-down is ever weakened.
             if (!MatchesRebootCountBounds(session, filter)) return false;
+            if (!MatchesConnectionType(session, filter)) return false;
             // AgentVersion / ImeAgentVersion (exact + prefix) are pushed to OData
             // in BuildSearchScanFilter — the server has already filtered them out
             // before we see the page. No client-side check needed.
@@ -951,9 +970,11 @@ namespace AutopilotMonitor.Functions.Services
                     && (s.ImeAgentVersion == null
                         || !s.ImeAgentVersion.StartsWith(filter.ImeAgentVersionPrefix!, StringComparison.OrdinalIgnoreCase)))
                     return false;
-                // Device-snapshot path has no RebootCount OData push-down — enforce it here so a
-                // deviceProperties + rebootCountMin query can't return sub-threshold sessions.
+                // Device-snapshot path has no RebootCount/ConnectionType OData push-down —
+                // enforce them here so a deviceProperties + rebootCountMin/connectionType
+                // query can't return non-matching sessions.
                 if (!MatchesRebootCountBounds(s, filter)) return false;
+                if (!MatchesConnectionType(s, filter)) return false;
                 return true;
             }).ToList();
         }

src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.Sessions.cs

@@ -225,6 +225,12 @@ namespace AutopilotMonitor.Functions.Services
             if (apiRequestCount.HasValue)
                 indexEntity["ApiRequestCount"] = apiRequestCount.Value;
 
+            // Connection-type projection (UpdateSessionConnectionTypeAsync merges this) —
+            // must be in this superset or a StartedAt-shift full upsert drops it.
+            var connectionType = sessionEntity.GetString("ConnectionType");
+            if (!string.IsNullOrEmpty(connectionType))
+                indexEntity["ConnectionType"] = connectionType;
+
             return indexEntity;
         }
 
@@ -398,6 +404,7 @@ namespace AutopilotMonitor.Functions.Services
                 string geoRegion = string.Empty;
                 string geoCity = string.Empty;
                 string geoLoc = string.Empty;
+                string? connectionType = null;
                 string? existingIndexRowKey = null;
                 // PR3: cascade-delete state-machine columns. Re-registration MUST preserve
                 // these — losing them would silently clear the lock and let the agent's writes
@@ -444,6 +451,7 @@ namespace AutopilotMonitor.Functions.Services
                     geoRegion = existingEntity.GetString("GeoRegion") ?? string.Empty;
                     geoCity = existingEntity.GetString("GeoCity") ?? string.Empty;
                     geoLoc = existingEntity.GetString("GeoLoc") ?? string.Empty;
+                    connectionType = existingEntity.GetString("ConnectionType");
                     existingIndexRowKey = existingEntity.GetString("IndexRowKey");
                     existingDeletionState = existingEntity.GetString("DeletionState");
                     existingPendingDeletionManifestId = existingEntity.GetString("PendingDeletionManifestId");
@@ -553,6 +561,12 @@ namespace AutopilotMonitor.Functions.Services
                 if (!string.IsNullOrEmpty(geoLoc))
                     entity["GeoLoc"] = geoLoc;
 
+                // Merge-mode field (UpdateSessionConnectionTypeAsync) — preserve through the
+                // Replace; the agent re-emits network_interface_info after restart, but the
+                // value must not be lost in the window until it does.
+                if (!string.IsNullOrEmpty(connectionType))
+                    entity["ConnectionType"] = connectionType;
+
                 // Preserve IndexRowKey through the Replace so that:
                 // 1. Concurrent UpdateSessionStatusAsync calls can find it (prevents index stale-status)
                 // 2. UpsertSessionIndexAsync can detect and delete old index entries when startedAt shifts
@@ -2714,6 +2728,52 @@ namespace AutopilotMonitor.Functions.Services
             }
         }
 
+        /// <summary>
+        /// Stores the active network connection type ("WiFi"/"Ethernet") from the latest
+        /// network_interface_info event (Merge-mode, single field, last-write-wins).
+        /// Same UpdateEntity-not-Upsert rationale as <see cref="UpdateSessionNetworkLatencyAsync"/>:
+        /// a tombstoned Sessions row must stay tombstoned (404 → no-op).
+        /// Non-fatal: failures are logged as warnings and do not block ingest.
+        /// </summary>
+        public async Task UpdateSessionConnectionTypeAsync(string tenantId, string sessionId,
+            string connectionType)
+        {
+            try
+            {
+                var tableClient = _tableServiceClient.GetTableClient(Constants.TableNames.Sessions);
+                var update = new TableEntity(tenantId, sessionId)
+                {
+                    ["ConnectionType"] = connectionType
+                };
+                await tableClient.UpdateEntityAsync(update, ETag.All, TableUpdateMode.Merge);
+
+                // Mirror to SessionsIndex — serves the session list and the cheap
+                // connectionType= search filter (OData eq push-down on the index).
+                var idxRef = await tableClient.GetEntityAsync<TableEntity>(
+                    tenantId, sessionId, select: new[] { "IndexRowKey" });
+                var indexRowKey = idxRef.Value.GetString("IndexRowKey");
+                if (!string.IsNullOrEmpty(indexRowKey))
+                {
+                    await MergeSessionIndexAsync(tenantId, indexRowKey,
+                        new TableEntity(tenantId, indexRowKey)
+                        {
+                            ["ConnectionType"] = connectionType
+                        });
+                }
+            }
+            catch (RequestFailedException ex) when (ex.Status == 404)
+            {
+                _logger.LogDebug(
+                    "UpdateSessionConnectionType no-op: Sessions row {Tenant}/{Session} is absent (tombstoned or never registered)",
+                    tenantId, sessionId);
+            }
+            catch (Exception ex)
+            {
+                // Non-fatal — don't block ingest
+                _logger.LogWarning(ex, "Failed to update connection type for session {SessionId}", sessionId);
+            }
+        }
+
         // ===== SESSION/EVENT MAPPING HELPERS =====
 
         /// <summary>
@@ -2809,6 +2869,7 @@ namespace AutopilotMonitor.Functions.Services
                 DurationSeconds = ComputeEffectiveDuration(entity, status, startedAt, completedAt),
                 AvgApiLatencyMs = SafeGetDouble(entity, "AvgApiLatencyMs"),
                 ApiRequestCount = SafeGetInt32(entity, "ApiRequestCount"),
+                ConnectionType = entity.GetString("ConnectionType"),
                 EnrollmentType = entity.GetString("EnrollmentType") ?? "v1",
                 DiagnosticsBlobName = entity.GetString("DiagnosticsBlobName"),
                 // Legacy rows that predate this field surface as null → download path treats

src/McpServer/autopilot-monitor-mcp/src/tools/admin.ts

@@ -894,6 +894,8 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
         isPreProvisioned: z.boolean().optional().describe('Filter pre-provisioned (white-glove) sessions'),
         isHybridJoin: z.boolean().optional().describe('Filter hybrid AAD-join sessions'),
         isSelfDeployingProfile: z.boolean().optional().describe('Filter self-deploying/kiosk profile sessions (CloudAssignedOobeConfig 0x20|0x40)'),
+        connectionType: z.enum(['WiFi', 'Ethernet']).optional()
+          .describe('Active network connection type ("WiFi" or "Ethernet", exact match on the indexed column; last emission wins). Sessions predating the projection lack the column and are excluded.'),
         fields: z.string().optional().describe('Comma-separated pass-through projection over the literal stored column names (case-insensitive, PascalCase, e.g. "Status,OsEdition,ImeAgentVersion,GeoCity"); narrows the row but never drops a real column. PartitionKey + RowKey are always kept. Omit for the full raw row.'),
         pageSize: z.coerce.number().int().min(1).max(1000).optional().default(200)
           .describe('Page size (1-1000, default 200). Returns this many sessions per call; follow nextLink to fetch more.'),
@@ -906,14 +908,14 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
       try {
         const { tenantId: rawTenantId, status, startedAfter, startedBefore, serialNumber, agentVersion, agentVersionPrefix,
           imeAgentVersion, imeAgentVersionPrefix, manufacturer, model, enrollmentType, deviceName, osBuild,
-          geoCountry, isPreProvisioned, isHybridJoin, isSelfDeployingProfile, fields, pageSize, continuation } = args;
+          geoCountry, isPreProvisioned, isHybridJoin, isSelfDeployingProfile, connectionType, fields, pageSize, continuation } = args;
         const tenantId = enforceDelegatedTenantForPage(rawTenantId, continuation);
         const basePath = pickGlobalOrTenantPath('/api/global/raw/sessions', '/api/raw/sessions', tenantId);
         const path = followNextLink(
           basePath,
           { tenantId, status, startedAfter, startedBefore, serialNumber, agentVersion, agentVersionPrefix,
             imeAgentVersion, imeAgentVersionPrefix, manufacturer, model, enrollmentType, deviceName, osBuild,
-            geoCountry, isPreProvisioned, isHybridJoin, isSelfDeployingProfile, fields, pageSize },
+            geoCountry, isPreProvisioned, isHybridJoin, isSelfDeployingProfile, connectionType, fields, pageSize },
           continuation,
         );
         const data = await apiFetch(path);

src/McpServer/autopilot-monitor-mcp/src/tools/sessions.ts

@@ -139,6 +139,10 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
                     'e.g. rebootCountMin=5. Only populated for v2 enrollments; sessions that predate the field are excluded.'),
         rebootCountMax: z.coerce.number().int().min(0).optional()
           .describe('Maximum number of reboots observed during enrollment (<=).'),
+        connectionType: z.enum(['WiFi', 'Ethernet']).optional()
+          .describe('Active network connection type during enrollment ("WiFi" or "Ethernet"), indexed for cheap exact-match ' +
+                    'filtering (e.g. "how many machines enrolled over WiFi?"). Last emission wins — a device that switches media ' +
+                    'mid-enrollment reports the most recent state. Sessions that predate the projection lack the column and are excluded.'),
         fields: z.string().optional()
           .describe('Comma-separated lean projection (e.g. "sessionId,status,agentVersion,startedAt"). ' +
                     'Use for counting / aggregation to avoid the response cap. Available: sessionId, tenantId, status, ' +
@@ -146,7 +150,8 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
                     'durationSeconds, currentPhase, failureReason, eventCount, enrollmentType, isPreProvisioned, ' +
                     'isUserDriven, isHybridJoin, isSelfDeployingProfile, agentVersion, imeAgentVersion, geoCountry, rebootCount, ' +
                     'avgApiLatencyMs, apiRequestCount (agent→backend HTTP round-trip; weight latency by apiRequestCount when aggregating, ' +
-                    'e.g. fields=geoCountry,avgApiLatencyMs,apiRequestCount for a per-country latency sweep; null on sessions from agents predating the field).'),
+                    'e.g. fields=geoCountry,avgApiLatencyMs,apiRequestCount for a per-country latency sweep; null on sessions from agents predating the field), ' +
+                    'connectionType ("WiFi"/"Ethernet"; null on sessions predating the projection).'),
         deviceProperties: z.record(z.string(), z.string()).optional().describe(
           'Dynamic device property filters. Keys use "eventType.propertyName" dot notation. ' +
           'See the device_properties catalog (call get_resource(name="device_properties")) for all available keys and types. ' +

src/Shared/AutopilotMonitor.Shared/Constants.cs

@@ -62,6 +62,13 @@ namespace AutopilotMonitor.Shared
         /// </summary>
         public const string ImeMatchLogPath = @"%ProgramData%\AutopilotMonitor\Logs\ime_pattern_matches.log";
 
+        /// <summary>
+        /// Default path for the gather rule debug trace file (debugging/diagnostics).
+        /// Written when the tenant enables EnableGatherRuleDebugLog; explains every
+        /// gather-rule evaluation decision, including outcomes that produce no event.
+        /// </summary>
+        public const string GatherRuleDebugLogPath = @"%ProgramData%\AutopilotMonitor\Logs\gather_rules_debug.log";
+
         /// <summary>
         /// Scheduled Task name used to run the agent as SYSTEM
         /// </summary>

src/Shared/AutopilotMonitor.Shared/DataAccess/ISessionRepository.cs

@@ -115,6 +115,13 @@ namespace AutopilotMonitor.Shared.DataAccess
         /// </summary>
         Task UpdateSessionNetworkLatencyAsync(string tenantId, string sessionId,
             double avgLatencyMs, int requestCount);
+        /// <summary>
+        /// Persists the active network connection type ("WiFi" or "Ethernet") from the
+        /// latest <c>network_interface_info</c> event. Last-write-wins; fail-soft like
+        /// the other supplementary-field updaters.
+        /// </summary>
+        Task UpdateSessionConnectionTypeAsync(string tenantId, string sessionId,
+            string connectionType);
 
         // --- Server→Agent Actions ---
         /// <summary>

src/Shared/AutopilotMonitor.Shared/Models/Config/AgentConfigResponse.cs

@@ -40,6 +40,12 @@ namespace AutopilotMonitor.Shared.Models
         /// </summary>
         public bool EnableImeMatchLog { get; set; } = false;
 
+        /// <summary>
+        /// Whether to write a local gather-rule evaluation trace file.
+        /// When true, the default path is used: Constants.GatherRuleDebugLogPath.
+        /// </summary>
+        public bool EnableGatherRuleDebugLog { get; set; } = false;
+
         public CollectorConfiguration Collectors { get; set; } = default!;
 
         /// <summary>

src/Shared/AutopilotMonitor.Shared/Models/Config/TenantConfiguration.cs

@@ -334,6 +334,15 @@ namespace AutopilotMonitor.Shared.Models
         /// </summary>
         public bool? EnableImeMatchLog { get; set; }
 
+        /// <summary>
+        /// Whether the agent writes a local gather-rule evaluation trace file so customers
+        /// can diagnose rules that produce no timeline events (scope skips, on_change
+        /// suppression, empty collector results, logparser details). When true, the agent
+        /// writes to Constants.GatherRuleDebugLogPath. The trace never leaves the device.
+        /// null = use agent default (false).
+        /// </summary>
+        public bool? EnableGatherRuleDebugLog { get; set; }
+
         /// <summary>
         /// Log verbosity level override for this tenant's agents.
         /// null = use agent default ("Info"). Values: "Info", "Debug", "Verbose", "Trace".

src/Shared/AutopilotMonitor.Shared/Models/SessionApiModels.cs

@@ -275,6 +275,14 @@ namespace AutopilotMonitor.Shared.Models
         /// </summary>
         public int? ApiRequestCount { get; set; }
 
+        /// <summary>
+        /// Active network connection type during enrollment: "WiFi" or "Ethernet".
+        /// Projected at ingest from the latest <c>network_interface_info</c> event
+        /// (last emission wins — a device that switches media mid-enrollment reports
+        /// the most recent state). Null for sessions that predate the projection.
+        /// </summary>
+        public string? ConnectionType { get; set; }
+
         /// <summary>
         /// Enrollment type: "v1" (Autopilot Classic/ESP) or "v2" (Windows Device Preparation).
         /// Defaults to "v1" for sessions that predate this field.

src/Shared/AutopilotMonitor.Shared/Models/SessionSearchFilter.cs

@@ -37,6 +37,11 @@ namespace AutopilotMonitor.Shared.Models
         public int? RebootCountMin { get; set; }
         public int? RebootCountMax { get; set; }
 
+        // Active network connection type ("WiFi" or "Ethernet"). Exact match on the
+        // stored ConnectionType column. Sessions that predate the projection lack the
+        // property and are excluded (acceptable — they have no connection data).
+        public string? ConnectionType { get; set; }
+
         public int Limit { get; set; } = 50;
 
         // Dynamic device property filters (key = "eventType.propertyName", value = filter expression)

src/Web/autopilot-monitor-web/app/admin/tenants/sections/SectionTenantConfigReport.tsx

@@ -58,6 +58,7 @@ interface TenantConfig {
   enableTimezoneAutoSet?: boolean | null;
   ntpServer?: string | null;
   enableImeMatchLog?: boolean | null;
+  enableGatherRuleDebugLog?: boolean | null;
   logLevel?: string | null;
   maxBatchSize?: number | null;
   showEnrollmentSummary?: boolean | null;
@@ -130,6 +131,7 @@ const DEFAULTS: Record<string, unknown> = {
   enableTimezoneAutoSet: null,
   ntpServer: 'time.windows.com',
   enableImeMatchLog: null,
+  enableGatherRuleDebugLog: null,
   logLevel: null,
   maxBatchSize: null,
   showEnrollmentSummary: null,
@@ -168,6 +170,7 @@ const RUNTIME_DEFAULTS: Record<string, unknown> = {
   enableTimezoneAutoSet: false,
   ntpServer: 'time.windows.com',
   enableImeMatchLog: false,
+  enableGatherRuleDebugLog: false,
   maxAuthFailures: 5,
   authFailureTimeoutMinutes: 0,
   logLevel: 'Info',
@@ -296,6 +299,7 @@ function computeRuntime(c: TenantConfig): Record<string, unknown> {
     enableTimezoneAutoSet: c.enableTimezoneAutoSet ?? false,
     ntpServer: c.ntpServer ?? 'time.windows.com',
     enableImeMatchLog: c.enableImeMatchLog ?? false,
+    enableGatherRuleDebugLog: c.enableGatherRuleDebugLog ?? false,
     maxAuthFailures: c.maxAuthFailures ?? 5,
     authFailureTimeoutMinutes: c.authFailureTimeoutMinutes ?? 0,
     logLevel: c.logLevel ?? 'Info',
@@ -575,6 +579,7 @@ export function SectionTenantConfigReport() {
                 <ConfigRow label="Timezone Auto-Set" value={config.enableTimezoneAutoSet} configKey="enableTimezoneAutoSet" defaults={DEFAULTS} />
                 <ConfigRow label="NTP Server" value={config.ntpServer} configKey="ntpServer" defaults={DEFAULTS} />
                 <ConfigRow label="IME Match Log" value={config.enableImeMatchLog} configKey="enableImeMatchLog" defaults={DEFAULTS} />
+                <ConfigRow label="Gather Rule Debug Log" value={config.enableGatherRuleDebugLog} configKey="enableGatherRuleDebugLog" defaults={DEFAULTS} />
                 <ConfigRow label="Log Level" value={config.logLevel} configKey="logLevel" defaults={DEFAULTS} />
                 <ConfigRow label="Max Batch Size" value={config.maxBatchSize} configKey="maxBatchSize" defaults={DEFAULTS} />
                 <ConfigRow label="Show Script Output" value={config.showScriptOutput} configKey="showScriptOutput" defaults={DEFAULTS} />
@@ -647,6 +652,7 @@ export function SectionTenantConfigReport() {
                     <ConfigRow label="Timezone Auto-Set" value={runtime.enableTimezoneAutoSet} configKey="enableTimezoneAutoSet" defaults={RUNTIME_DEFAULTS} />
                     <ConfigRow label="NTP Server" value={runtime.ntpServer} configKey="ntpServer" defaults={RUNTIME_DEFAULTS} />
                     <ConfigRow label="IME Match Log" value={runtime.enableImeMatchLog} configKey="enableImeMatchLog" defaults={RUNTIME_DEFAULTS} />
+                    <ConfigRow label="Gather Rule Debug Log" value={runtime.enableGatherRuleDebugLog} configKey="enableGatherRuleDebugLog" defaults={RUNTIME_DEFAULTS} />
                     <ConfigRow label="Log Level" value={runtime.logLevel} configKey="logLevel" defaults={RUNTIME_DEFAULTS} />
                     <ConfigRow label="Send Trace Events" value={runtime.sendTraceEvents} configKey="sendTraceEvents" defaults={RUNTIME_DEFAULTS} />
                     <ConfigRow label="Unrestricted Mode" value={runtime.unrestrictedMode} configKey="unrestrictedMode" defaults={RUNTIME_DEFAULTS} />

src/Web/autopilot-monitor-web/app/dashboard/components/SessionTable.tsx

@@ -31,6 +31,7 @@ const ALL_COLUMNS: ColumnDef[] = [
   { key: "started", label: "Started", defaultVisible: true, sortKey: "startedAt" },
   { key: "country", label: "Country", defaultVisible: false, sortKey: "geoCountry", filterKey: "geoCountry" },
   { key: "apiLatency", label: "API Latency", defaultVisible: false, sortKey: "avgApiLatencyMs" },
+  { key: "connection", label: "Connection", defaultVisible: false, sortKey: "connectionType", filterKey: "connectionType" },
   { key: "agentVersion", label: "Agent Version", defaultVisible: false, sortKey: "agentVersion", filterKey: "agentVersion" },
   { key: "osName", label: "OS Name", defaultVisible: false, sortKey: "osName", filterKey: "osName" },
   { key: "osBuild", label: "OS Build", defaultVisible: false, sortKey: "osBuild", filterKey: "osBuild" },
@@ -641,7 +642,7 @@ export function SessionTable({
                       currentSort={sortColumn}
                       direction={sortDirection}
                       onSort={onSort}
-                      className={["eventCount", "duration", "started", "country", "apiLatency", "agentVersion", "osName", "osBuild", "osDisplayVersion", "osEdition", "osLanguage"].includes(col.key) ? "px-3" : undefined}
+                      className={["eventCount", "duration", "started", "country", "apiLatency", "connection", "agentVersion", "osName", "osBuild", "osDisplayVersion", "osEdition", "osLanguage"].includes(col.key) ? "px-3" : undefined}
                       filterKey={col.filterKey}
                       filterValues={col.filterKey ? uniqueValuesByField[col.filterKey] : undefined}
                       activeFilter={col.filterKey ? columnFilters[col.filterKey] : undefined}
@@ -922,6 +923,19 @@ function SessionCell({
         </td>
       );
 
+    case "connection":
+      return (
+        <td className="px-3 py-4 whitespace-nowrap text-sm text-gray-500">
+          {session.connectionType ? (
+            <span title="Active network connection during enrollment (last reported state)">
+              {session.connectionType}
+            </span>
+          ) : (
+            <span className="text-gray-300">—</span>
+          )}
+        </td>
+      );
+
     case "agentVersion": {
       const fullVersion = session.agentVersion || "";
       const shortVersion = fullVersion.split("+")[0];

src/Web/autopilot-monitor-web/app/sessions/[sessionId]/components/EventTimeline.tsx

@@ -355,6 +355,24 @@ function PhaseSection({
   );
 }
 
+// Backfilled events (ModernDeploymentTracker error backfill): pre-agent event-log records
+// replayed at agent start carry backfilled=true plus the original event-log timeCreated —
+// the event's own timestamp is agent emission time, so without this the whole block renders
+// with one identical (wrong) time and full Error severity, reading like a live failure.
+function getBackfillInfo(event: EnrollmentEvent): { isBackfilled: boolean; recordedAt: Date | null } {
+  const raw = event.data?.backfilled ?? event.data?.Backfilled;
+  const isBackfilled = raw === true || raw === "true" || raw === "True";
+  if (!isBackfilled) return { isBackfilled: false, recordedAt: null };
+  const t = event.data?.timeCreated ?? event.data?.TimeCreated;
+  const recordedAt = typeof t === "string" && t !== "" && !isNaN(Date.parse(t)) ? new Date(t) : null;
+  return { isBackfilled, recordedAt };
+}
+
+const BACKFILL_TOOLTIP =
+  "Recorded by Windows before the agent started — replayed from the event log for visibility. " +
+  "If enrollment progressed afterwards, this error was already resolved by a retry. " +
+  "The timestamp shown is the original event-log time.";
+
 function EventRow({ event, showScriptOutput }: { event: EnrollmentEvent; showScriptOutput?: boolean }) {
   const [showDetails, setShowDetails] = useState(false);
   const [showRaw, setShowRaw] = useState(false);
@@ -429,15 +447,28 @@ function EventRow({ event, showScriptOutput }: { event: EnrollmentEvent; showScr
   const hasData = isTruncated || (detailData && Object.keys(detailData).length > 0);
   const hasDetails = true; // Every event has at least the metadata block
 
+  const { isBackfilled, recordedAt } = getBackfillInfo(event);
+
   return (
     <div id={`event-${event.eventId}`} className="bg-gray-50 rounded-lg p-3 hover:bg-gray-100 transition-colors">
       <div className="flex items-start justify-between">
         <div className="flex-1 min-w-0">
           <div className="flex items-center gap-3">
             <span className="text-xs text-gray-500 font-mono">
-              {new Date(event.timestamp).toLocaleTimeString()}
+              {(recordedAt ?? new Date(event.timestamp)).toLocaleTimeString()}
+              {recordedAt && (
+                <span className="text-gray-400 font-sans"> (reported {new Date(event.timestamp).toLocaleTimeString()})</span>
+              )}
             </span>
             <SeverityBadge severity={event.severity} />
+            {isBackfilled && (
+              <span
+                className="px-2 py-0.5 rounded text-xs font-medium bg-slate-200 text-slate-600"
+                title={BACKFILL_TOOLTIP}
+              >
+                ⟲ Backfilled
+              </span>
+            )}
             <span className="text-sm font-medium text-gray-900">{event.eventType}</span>
           </div>
           <p className="mt-1 text-sm text-gray-600" title={event.message || undefined}>{shortenBuildHashInMessage(event.message)}</p>
@@ -608,6 +639,15 @@ function EventRow({ event, showScriptOutput }: { event: EnrollmentEvent; showScr
               <span className="w-16 flex-shrink-0 text-gray-400">EventId</span>
               <span className="font-mono">{event.eventId}</span>
             </div>
+            {recordedAt && (
+              <div className="flex mt-0.5">
+                <span className="w-16 flex-shrink-0 text-gray-400">Recorded</span>
+                <span className="font-mono">
+                  {recordedAt.toISOString().replace('T', ' ').replace('Z', '')}
+                  <span className="text-gray-400 ml-1" title={BACKFILL_TOOLTIP}>(event log, pre-agent)</span>
+                </span>
+              </div>
+            )}
             <div className="flex mt-0.5">
               <span className="w-16 flex-shrink-0 text-gray-400">Created</span>
               <span className="font-mono">{event.timestamp}</span>
@@ -751,6 +791,7 @@ function RawEventRow({ event }: { event: EnrollmentEvent }) {
   const [expanded, setExpanded] = useState(false);
   const detailData = useMemo(() => normalizeEventDataForDisplay(event.data), [event.data]);
   const hasDetails = detailData && Object.keys(detailData).length > 0;
+  const { isBackfilled, recordedAt } = getBackfillInfo(event);
 
   const sevColor: Record<string, string> = {
     Trace: "text-purple-500",
@@ -765,8 +806,11 @@ function RawEventRow({ event }: { event: EnrollmentEvent }) {
     <div id={`event-${event.eventId}`} className="py-1.5 text-xs font-mono">
       <div className="flex items-start gap-2">
         <span className="text-gray-400 w-8 text-right flex-shrink-0">{event.sequence}</span>
-        <span className="text-gray-500 flex-shrink-0">{new Date(event.timestamp).toLocaleTimeString()}</span>
+        <span className="text-gray-500 flex-shrink-0">{(recordedAt ?? new Date(event.timestamp)).toLocaleTimeString()}</span>
         <span className={`flex-shrink-0 w-14 ${sevColor[event.severity] || "text-gray-500"}`}>{event.severity}</span>
+        {isBackfilled && (
+          <span className="text-slate-500 flex-shrink-0" title={BACKFILL_TOOLTIP}>⟲</span>
+        )}
         <span className="text-gray-900 font-medium flex-shrink-0">{event.eventType}</span>
         <span className="text-gray-500 truncate flex-1 min-w-0" title={event.message || undefined}>{shortenBuildHashInMessage(event.message)}</span>
         {hasDetails && (

src/Web/autopilot-monitor-web/app/settings/TenantConfigContext.tsx

@@ -167,6 +167,8 @@ interface TenantConfigContextValue {
   setEnableTimezoneAutoSet: (v: boolean) => void;
   enableImeMatchLog: boolean;
   setEnableImeMatchLog: (v: boolean) => void;
+  enableGatherRuleDebugLog: boolean;
+  setEnableGatherRuleDebugLog: (v: boolean) => void;
   logLevel: string;
   setLogLevel: (v: string) => void;
   showScriptOutput: boolean;
@@ -384,6 +386,7 @@ export function TenantConfigProvider({ children }: { children: React.ReactNode }
   const [enableGeoLocation, setEnableGeoLocation] = useState(true);
   const [enableTimezoneAutoSet, setEnableTimezoneAutoSet] = useState(false);
   const [enableImeMatchLog, setEnableImeMatchLog] = useState(false);
+  const [enableGatherRuleDebugLog, setEnableGatherRuleDebugLog] = useState(false);
   const [logLevel, setLogLevel] = useState("Info");
   const [showScriptOutput, setShowScriptOutput] = useState(true);
   const [showEnrollmentSummary, setShowEnrollmentSummary] = useState(false);
@@ -503,6 +506,7 @@ export function TenantConfigProvider({ children }: { children: React.ReactNode }
         setEnableGeoLocation(data.enableGeoLocation ?? true);
         setEnableTimezoneAutoSet(data.enableTimezoneAutoSet ?? false);
         setEnableImeMatchLog(data.enableImeMatchLog ?? false);
+        setEnableGatherRuleDebugLog(data.enableGatherRuleDebugLog ?? false);
         setLogLevel(data.logLevel ?? "Info");
         setShowScriptOutput(data.showScriptOutput ?? true);
         setShowEnrollmentSummary(data.showEnrollmentSummary ?? false);
@@ -700,6 +704,7 @@ export function TenantConfigProvider({ children }: { children: React.ReactNode }
         enableGeoLocation,
         enableTimezoneAutoSet,
         enableImeMatchLog,
+        enableGatherRuleDebugLog,
         logLevel,
         showScriptOutput,
         showEnrollmentSummary,
@@ -777,7 +782,7 @@ export function TenantConfigProvider({ children }: { children: React.ReactNode }
     manufacturerWhitelist, modelWhitelist, validateAutopilotDevice, validateCorporateIdentifier, validateDeviceAssociation,
     dataRetentionDays, sessionTimeoutHours, enablePerformanceCollector, performanceCollectorInterval,
     helloWaitTimeoutSeconds, selfDestructOnComplete, keepLogFile, rebootOnComplete, rebootDelaySeconds,
-    contactEmail, enableGeoLocation, enableTimezoneAutoSet, enableImeMatchLog, logLevel, showScriptOutput, showEnrollmentSummary,
+    contactEmail, enableGeoLocation, enableTimezoneAutoSet, enableImeMatchLog, enableGatherRuleDebugLog, logLevel, showScriptOutput, showEnrollmentSummary,
     enrollmentSummaryTimeoutSeconds, enrollmentSummaryBrandingImageUrl, enrollmentSummaryLaunchRetrySeconds,
     notificationChannels,
     slaTargetSuccessRate, slaTargetMaxDurationMinutes, slaTargetAppInstallSuccessRate,
@@ -1113,6 +1118,7 @@ export function TenantConfigProvider({ children }: { children: React.ReactNode }
     setEnableGeoLocation(config.enableGeoLocation ?? true);
     setEnableTimezoneAutoSet(config.enableTimezoneAutoSet ?? false);
     setEnableImeMatchLog(config.enableImeMatchLog ?? false);
+    setEnableGatherRuleDebugLog(config.enableGatherRuleDebugLog ?? false);
     setLogLevel(config.logLevel ?? "Info");
     setShowScriptOutput(config.showScriptOutput ?? true);
     setShowEnrollmentSummary(config.showEnrollmentSummary ?? false);
@@ -1542,6 +1548,7 @@ export function TenantConfigProvider({ children }: { children: React.ReactNode }
       enableGeoLocation, setEnableGeoLocation,
       enableTimezoneAutoSet, setEnableTimezoneAutoSet,
       enableImeMatchLog, setEnableImeMatchLog,
+      enableGatherRuleDebugLog, setEnableGatherRuleDebugLog,
       logLevel, setLogLevel,
       showScriptOutput, setShowScriptOutput,
       showEnrollmentSummary, setShowEnrollmentSummary,

src/Web/autopilot-monitor-web/app/settings/agent/sections/SectionAgentSettings.tsx

@@ -17,6 +17,7 @@ export function SectionAgentSettings() {
     enableGeoLocation, setEnableGeoLocation,
     enableTimezoneAutoSet, setEnableTimezoneAutoSet,
     enableImeMatchLog, setEnableImeMatchLog,
+    enableGatherRuleDebugLog, setEnableGatherRuleDebugLog,
     logLevel, setLogLevel,
     showScriptOutput, setShowScriptOutput,
     showEnrollmentSummary, setShowEnrollmentSummary,
@@ -51,6 +52,8 @@ export function SectionAgentSettings() {
         setEnableTimezoneAutoSet={setEnableTimezoneAutoSet}
         enableImeMatchLog={enableImeMatchLog}
         setEnableImeMatchLog={setEnableImeMatchLog}
+        enableGatherRuleDebugLog={enableGatherRuleDebugLog}
+        setEnableGatherRuleDebugLog={setEnableGatherRuleDebugLog}
         logLevel={logLevel}
         setLogLevel={setLogLevel}
         showScriptOutput={showScriptOutput}

src/Web/autopilot-monitor-web/app/settings/components/AgentSettingsSection.tsx

@@ -24,6 +24,8 @@ interface AgentSettingsSectionProps {
   setEnableTimezoneAutoSet: (value: boolean) => void;
   enableImeMatchLog: boolean;
   setEnableImeMatchLog: (value: boolean) => void;
+  enableGatherRuleDebugLog: boolean;
+  setEnableGatherRuleDebugLog: (value: boolean) => void;
   logLevel: string;
   setLogLevel: (value: string) => void;
   showScriptOutput: boolean;
@@ -64,6 +66,8 @@ export default function AgentSettingsSection({
   setEnableTimezoneAutoSet,
   enableImeMatchLog,
   setEnableImeMatchLog,
+  enableGatherRuleDebugLog,
+  setEnableGatherRuleDebugLog,
   logLevel,
   setLogLevel,
   showScriptOutput,
@@ -199,6 +203,21 @@ export default function AgentSettingsSection({
             </button>
           </div>
 
+          {/* Gather Rule Debug Log */}
+          <div className="flex items-center justify-between p-4 rounded-lg border border-gray-200 hover:border-violet-200 transition-colors">
+            <div>
+              <p className="font-medium text-gray-900">Gather Rule Debug Log</p>
+              <p className="text-sm text-gray-500">
+                Trace gather rule evaluation to a local file to diagnose rules that produce no timeline events. The trace never leaves the device.
+                {enableGatherRuleDebugLog && <span className="block text-xs text-gray-400 mt-0.5 font-mono">%ProgramData%\AutopilotMonitor\Logs\gather_rules_debug.log</span>}
+              </p>
+            </div>
+            <button onClick={() => setEnableGatherRuleDebugLog(!enableGatherRuleDebugLog)}
+              className={`relative inline-flex h-6 w-11 flex-shrink-0 items-center rounded-full transition-colors ${enableGatherRuleDebugLog ? 'bg-violet-500' : 'bg-gray-300'}`}>
+              <span className={`inline-block h-4 w-4 transform rounded-full bg-white transition-transform ${enableGatherRuleDebugLog ? 'translate-x-6' : 'translate-x-1'}`} />
+            </button>
+          </div>
+
           {/* Show Script Output */}
           <div className="flex items-center justify-between p-4 rounded-lg border border-gray-200 hover:border-violet-200 transition-colors">
             <div className="flex-1">

src/Web/autopilot-monitor-web/app/settings/types.ts

@@ -60,6 +60,7 @@ export interface TenantConfiguration {
   enableGeoLocation?: boolean;
   enableTimezoneAutoSet?: boolean;
   enableImeMatchLog?: boolean;
+  enableGatherRuleDebugLog?: boolean;
   logLevel?: string;
   // Teams notifications (legacy)
   teamsWebhookUrl?: string;

src/Web/autopilot-monitor-web/components/GlobalSidebar.tsx

@@ -315,10 +315,9 @@ export function GlobalSidebar({ children }: { children: ReactNode }) {
   // Every nav Link below sets prefetch={false} on purpose. The sidebar renders the whole
   // navigation on every page, so the App Router's default viewport prefetch fires one RSC
   // request per visible link against the SWA-hosted Next.js runtime on each page load
-  // (measured: ~10k requests / 14 days). That host speaks HTTP/1.1, so those prefetches
-  // occupy the browser's 6 connections to the SAME origin that serves the document and the
-  // route chunks — when the runtime queues them (p95 ~0.9s but a tail reaching 150s+), the
-  // portal freezes until the queue drains. Every route here is a client component behind
+  // (measured: ~10k requests / 14 days). The SSR runtime queues that burst server-side and
+  // drains it all at once (p95 ~0.9s but a tail reaching 150s+), so the navigation the user
+  // actually wants is stuck behind it and the portal freezes. Every route here is a client component behind
   // ProtectedRoute that fetches its own data after mount, so the prefetched RSC payload
   // buys nothing. See docs/web/portal-navigation-prefetch.md.
   // --- Render a global nav link ---

src/Web/autopilot-monitor-web/types/session.ts

@@ -47,6 +47,8 @@ export interface Session {
   avgApiLatencyMs?: number;
   /** Number of HTTP requests behind avgApiLatencyMs — the weight when averaging across sessions. */
   apiRequestCount?: number;
+  /** Active network connection type during enrollment ("WiFi" or "Ethernet", last emission wins). Absent for sessions predating the projection. */
+  connectionType?: string;
   /**
    * Compact JSON snapshot of "last known session state" written by the maintenance
    * 5h-timeout sweep when a session graduates to terminal Failed (Hybrid User-Driven