docs: truth sweep — retire stale registers, reconcile ledgers with shipped state

- deferred.md: DELETED (git rm) — stale 2026-07-10 duplicate of the canonical
  deferred-work register; this completes archreview R2-08 T11 (the file was
  tracked, not untracked as the task assumed)
- ScadaBridge-docs-issues.md, ScadaBridge-docs-fixed.md: DELETED (git rm) —
  generated 2026-07-10 CommentChecker reports, already consumed; completes
  R2-08 T13 (also tracked, not untracked)
- stillpending.md: prepended historical-snapshot banner (2026-06-15 audit;
  Tier-1 table is not current open work)
- docs/plans/phase-8-checklist.md: replaced the unevidenced 'Complete / All
  passing' stub with the honest state per register row 25 (WP-4 target-scale
  load test never run)
- archreview/plans/00-MASTER-TRACKER.md: R2-01 T2 live failover drill
  annotated RESOLVED 2026-08-01 (PLAN-R2-01 T4 + docker/failover-drill.sh +
  SbrFailoverTests); R2-08 T11/T13 recorded completed by this sweep
- docs/plans/2026-07-22-clusterclient-to-grpc-plan.md: P3 deferred-RPCs note
  updated (all four live-proven 2026-08-01, 1c99d6fa); ClusterClientSiteAuditClient
  naming follow-up marked DONE (63c16d69)
- docs/plans/2026-05-28-opcua-tag-browser.md.tasks.json: Task 19 flipped to
  completed (manual smoke PASS 2026-08-01, 6dc5d94c)
- archreview/plans/PLAN-R2-0[1-8]*.tasks.json: all-pending manifests reconciled
  with the authoritative tracker (round 2 merged @ 1930f19b) — flipped to
  completed except R2-08 T1/T2 which remain pending needs-user
- docs/operations/2026-07-16-secrets-clustered-master-key.md: correction banner
  (SQL-hub replication shipped 8e12f994; KEK-rotation + clustered-secrets
  runbooks ship with ZB.MOM.WW.Secrets)
- docs/plans/2026-07-19-localdb-phase2-live-gate.md: external-system-delete
  observation annotated RESOLVED (2d03f2d5 reconciles deletions incl.
  external_systems)

Claude-Session: https://claude.ai/code/session_014WNM4vjoVksyyBraTXSZE1

docs/plans/phase-8-checklist.md

@@ -1,5 +1,23 @@
 # Phase 8 Execution Checklist
 
-**Status**: Complete
-**Tests**: All passing
-**Build**: 0 errors, 0 warnings
+**Update 2026-08-07 (truth sweep):** This checklist previously read
+"Status: Complete / Tests: All passing / Build: 0 errors, 0 warnings" — a
+107-byte stub with no per-work-package results and no linked run. That claim
+was **unevidenced** and has been retired.
+
+Honest state, per the deferred-work register
+(`2026-07-08-deferred-work-register.md`, row 25):
+
+- The **Phase-8 WP-4 target-scale load test** (10 sites × 500 instances ×
+  75 tags = 37,500 subscriptions/site, ~375,000 total) has **never been run**.
+- Nearest real coverage is arithmetic/aggregation only —
+  `PerformanceTests/StaggeredStartupTests.cs`
+  (`TagCapacity_75TagsPer500Machines_37500Total`) and
+  `HealthAggregationTests` — plus a single-subscriber 100k-event
+  `Streaming/SiteStreamThroughputTests.cs`. No sustained multi-site run
+  exists anywhere in `tests/` or `docker/`.
+- Revisit trigger: before any production go-live at target scale, or the
+  first site approaching ~500 instances / ~37.5k subscriptions.
+
+See `phase-8-production-readiness.md:152-170` (WP-4) and `:314-320`
+(test protocol) for the original scope.