perf(maintenance): one projected 35d Sessions scan shared by all rolling sweeps

The cross-tenant StartedAt-only date-range query is a full-table drain in
Table Storage; time attribution, device journeys, verdict calibration and the
calibration radar's tenant discovery each ran their own — four identical reads
per 2h tick. RunAllAsync / RunManualAsync now load the window once through
GetMaintenanceWindowSessionsAsync (MaintenanceSweepSessionProjection: the union
of the sweeps' columns, drops FailureSnapshotJson/geo/OS/diagnostics) and the
sweeps slice it by StartedAt. MaintenanceSweepProjectionEquivalenceTests pins
that every consumed field survives the projection.

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

docs/backend/device-journeys.md

@@ -78,7 +78,8 @@ Durations shown for attempts are the sessions' authoritative `DurationSeconds` v
   completed journeys, first-time-right count, attempt histogram, junk-serial exclusion
   count, `JourneyVersion`. A journey buckets on the StartedAt date of its completing
   success session (the platform's StartedAt-date convention; late terminals converge via
-  the sweep). All counts are **additive**, so a window rate is the ratio of summed daily
+  the sweep, which slices the tick's shared projected window scan — see
+  `time-attribution.md`). All counts are **additive**, so a window rate is the ratio of summed daily
   rows — there is no rolling-window row (unlike the median-based time-attribution
   aggregates, which cannot merge). 180-day retention. Rows exist below the ≥20 UI gate
   on purpose (the UI needs the n for "insufficient data (n=…)").

docs/backend/time-attribution.md

@@ -105,6 +105,11 @@ the partition).
 * Self-healing 30-day maintenance sweep (2h tick): backfills missing breakdowns, folds
   late-terminating sessions into their StartedAt-date aggregates, and enforces version
   purity — a stale-version row whose events aged out counts as missing, never mixed.
+  Reads the tick's **shared window scan** (`MaintenanceService.LoadSweepWindowSessionsAsync`,
+  one projected 35-day cross-tenant drain via `MaintenanceSweepSessionProjection` that
+  also feeds the device-journey and verdict-calibration sweeps) — the StartedAt-only
+  filter is a full-table read in Table Storage, so it is done once per tick, not once per
+  sweep; `MaintenanceSweepProjectionEquivalenceTests` pins the column set.
 * `TimeAttributionAggregates` (PK = TenantId or `global`, RK = `{yyyy-MM-dd}|{class}` and
   `rolling30|{class}`): per enrollment class (`user_driven`, `whiteglove`, `self_deploying`,
   `device_preparation` — never mixed) median/p75/p90 per segment over the fixed six-segment

docs/backend/verdict-calibration.md

@@ -84,7 +84,10 @@ Buckets[], ComputedAt }` with one bucket per (VerdictPath, Status):
 
 `MaintenanceService.SweepVerdictCalibrationAsync` (2-hourly, after the device-journey sweep
 so the chains are fresh; manual maintenance parity; kill switch
-`VerdictCalibrationSweepDisabled`) recomputes the rolling 30-day window whole (Replace),
+`VerdictCalibrationSweepDisabled`) slices the tick's shared projected window scan
+(`LoadSweepWindowSessionsAsync` — one 35-day cross-tenant drain feeds the time-attribution,
+device-journey and calibration sweeps plus the radar's tenant discovery; the StartedAt-only
+filter is a full-table read, so never per sweep), recomputes the rolling 30-day window whole (Replace),
 deletes stale date rows it did not regenerate, and the unbounded-tables cleanup applies the
 180-day retention. Sessions inside a deletion cascade are skipped; the table is regenerable
 and is wiped with the tenant on offboarding.

docs/log.md

@@ -2,6 +2,7 @@
 
 ## 2026-08-23
 
+* **Update**: `backend/time-attribution.md`, `backend/device-journeys.md`, `backend/verdict-calibration.md` — the rolling maintenance sweeps (time attribution, device journeys, verdict calibration, calibration-radar discovery) now share ONE projected 35-day cross-tenant Sessions scan per tick (`LoadSweepWindowSessionsAsync` + `MaintenanceSweepSessionProjection`, pinned by `MaintenanceSweepProjectionEquivalenceTests`) instead of four full-table drains; each sweep slices its own window by StartedAt.
 * **New**: `backend/verdict-calibration.md` — the classifier thermometer: every status write now stamps `VerdictPath` (required parameter on `UpdateSessionStatusAsync`; `EnrollmentTimeoutClassifier` returns its rule id), overriding a verdict preserves `PriorStatus`/`PriorVerdictPath`, `VerdictPathDerivation` attributes pre-instrumentation rows read-side (`legacy:*` when ambiguous). New daily aggregate `VerdictCalibrationAggregates` (per-path count/derived/eligible7d/reEnrolled7d/overridden-by-admin|late|other, sweep after the device-journey pass, 180d retention), `GET global/metrics/verdict-calibration`, MCP `get_verdict_calibration`, admin metrics section, and the `VerdictCalibrationRadar` (share / silence-share / r6 evidence-gap episodes in the tracker keyspace `verdictcalibration|`, `VerdictCalibrationDrift` ops event, no tenant bell).
 * **New**: `backend/silent-session-classification.md` — one place for the silent-session verdict: `EnrollmentTimeoutClassifier` rule order incl. the new rule 1c `IsSelfDeployingProvisioned` (self-deploying profile + Device Setup all-succeeded + no explicit failure ⇒ Succeeded reconcile, no grace/AwaitingUser — kiosk tenant aebdce78 audit: 836 finished devices parked AwaitingUser/Incomplete), the sweep stage-1 gates (`TryMarkWhiteGloveAwaitingUserAsync`, new `TryReconcileSelfDeployingAsync`), the ingest callers (max-lifetime, late-telemetry heal, stall probe) and the new admin retro mode `self_deploying_silent` (`GetSelfDeployingSilentSessionsAsync`). Agent companion: `SessionRegistrationHelper` waits up to 15s for a network link and retries 6× (~62s) instead of 5× (~30s) so the reboot relaunch on Wi-Fi no longer exits 7 before the link is back.
 * **New**: `agent/diagnostics-package.md` — the diagnostics ZIP's built-in collection is now ONE catalog in Shared (`DiagnosticsBuiltInSections.All`): the agent iterates it in order and the backend serves the same list to the portal (`GET diagnostics/paths`, MemberRead), so what administrators see is exactly what the agent collects. New conditional sections: RealmJoin client/package/Chocolatey/per-user logs behind the tenant's RealmJoin Watcher toggle (mirrored onto `AgentConfiguration.EnableRealmJoinWatcher` by the merger) and the Device Preparation bootstrapper event log behind the deterministic WDP marker (probe once per build, fail toward Classic); every skip is a manifest line. Built-ins bypass `DiagnosticsPathGuards` by design (reviewed code, `%ProgramData%\RealmJoin` is not allowlisted); caps/reparse/evtx export still apply. `MergeDiagnosticsLogPaths` dedups global ∪ tenant paths. Portal: collapsed read-only catalog + one-line rows in both cards, tenant context dropped the GA-only global fetch.