docs: F-CRIT-1 + F-A1 shipped (controller v0.179.0); invariant rule

Both marked SHIPPED + PROVEN-LIVE in OPEN-ITEMS and the campaign doc. All three
of Campaign 8's alarm findings are now closed (F-CRIT-1, F-CRIT-2, F-A1).

Adds the standing rule earned by this arc to the versioned workspace CLAUDE.md:
a comment asserting an invariant needs a test pinning it, or it is a wish — with
all six shipped-false-guarantee instances catalogued, and the corollary that a
test should assert the CONSEQUENCE (does the alarm fire?) not the MECHANISM
(does suppression expire?).

documentation/backlog/OPEN-ITEMS.md

@@ -24,7 +24,8 @@ State: `BLOCKED` · `READY` · `WAITING-ON-OPERATOR` · `WATCHING`. Every row ha
 | **R-97** | ~~Whole-guest backup tier had no hub signal; quiesce blamed the apps~~ | **SHIPPED** (controller v0.177.0 + hub v0.78.0/v0.79.0, 2026-07-27) | — | v0.79.0 (R-97c) replaced a FALSE operator-only comment with a real `operatorOnlyEvents` register | — |
 | **F-CRIT-2** | ~~A failed offsite backup left a phantom snapshot (1 B, manifest-less, NEWEST) that RESET the tier's freshness clock — 7 days silent on the real 168h cadence, invisible to both the R-88 breaker and the hub deadline monitor~~ | **SHIPPED + PROVEN-LIVE** (agent v0.106.0, 2026-07-28) | — | `NewestArchiveTime` now counts only plausibly-complete entries (measured 1 MiB floor; undecidable ⇒ not counted). Campaign fault 2 replayed on demo-hp: phantom rejected + logged once, tier correctly DUE and backed up, and **no thrash** on the inverse | — |
 | **R-99** | Server-side prune **never removes** a phantom snapshot. Confirmed it does NOT count them toward `keep-last` (dry-run kept 2 real + the phantom) so there is **no retention/data-loss bug** — but one accumulates per aborted upload, forever | READY (S) | — | Decide a cleanup path. Deletion on a **customer** datastore is a separate ruling — detection shipped, removal deliberately not automated | CC |
-| **F-CRIT-1** | An app that **fails to restart** after a quiesce never alarms on any channel. Two independent causes: `restartAll` discards the error (returns nothing), and `StateStopped` is whitelisted at `main.go:1237` on invariant I1, which is false for the failed-restart path | **READY — HIGHEST** | — | Campaign 8's other HIGH finding, untouched by the F-CRIT-2 fix. Evidence: `audits/CAMPAIGN-8-backup-restore-2026-07-27.md` | CC |
+| **F-CRIT-1** | ~~An app that **fails to restart** after a quiesce never alarms on any channel — `restartAll` discarded the error AND `StateStopped` was whitelisted on invariant I1, which the quiesce path had made false~~ | **SHIPPED + PROVEN-LIVE** (controller v0.179.0, 2026-07-28) | — | Both causes fixed. Live on demo-hp: alarmed 9s after grace expiry, banner shows `(stopped)`; a deliberate user stop stayed silent through 9 dead-app scans | — |
+| **F-A1** | ~~A restore-test in flight made a healthy backup report as FAILED (HTTP 409 read as a tier failure): breaker armed + operator emailed, on both boxes~~ | **SHIPPED + PROVEN-LIVE** (controller v0.179.0, 2026-07-28) | — | 409 → contention: tier stays DUE, dropped before anything stops (15m), and BLOCKED alarm if contention outlives the agent's 120m ceiling (3h). Hub DB: 409 → **0** operator emails, real failure → **1** | — |
 | **R-89** | Retention as a per-customer **commercial** policy on the hub | READY (increment 2) | — | Policy object + reconciler → ep0 prune job; keep box tokens write-only | CC |
 | **R-92** | Hub PBS-DR gauge is 0.1 GB-granular — small deltas unverifiable | READY (XS) | — | Widen precision when retention becomes customer-visible | CC |
 | **R-93** | `drill-r50` is both a blocked customer and the only drift fixture | READY (XS) | — | Retire it for a synthetic fixture, or unblock + silence per-customer | CC |