R-97: a failing backup is heard, and stops blaming the apps (v0.177.0)

R-97a: internal/quiesce had no route to the hub at all — three failed whole-guest
backups on 2026-07-27 produced zero events. TierNotifier is a seam (not an import),
wired by an init-only setter because main.go builds the notifier after the loop.
Edge-triggered: the failure fires when the R-88 breaker ARMS, not per retry, and
recovery rides recordSuccess's existing bool. Uses NEW operator-only event types;
reusing backup_failed would have emailed the customer in Hungarian about a backup
they cannot act on, since it has a customerMessages entry and is in live
enabled_events. Requires hub >= v0.78.0.

R-97b: v0.164.0's state filter cannot see an app caught MID-RESTART, which is how
BookStack alarmed. The fix is a suppression window keyed to the quiesce CYCLE,
consumed at the same single derivation point. 180s grace, derived from the deploy
flow's 120s health timeout and Mealie's 60s start_period; it expires, so an app
that genuinely fails to come back still alarms.

REUSE.md

@@ -74,6 +74,8 @@
 | `Loop.writeMarker` / `Recover` | controller/internal/quiesce/quiesce.go | `(m Marker)` / `()` | Quiesce crash-safety | Marker written BEFORE stopping stacks; Recover restarts stranded stacks at boot |
 | `quiesce.TieredBackend` + `Loop.resolveDueTiers` / `quiesceAndPollTiers` | controller/internal/quiesce/tiers.go, quiesce.go | `Tiers/DueFor/StartBackupFor/BackupStatusFor`; `resolveDueTiers(ctx) ([]dueTier,bool,error)` | THE R-82 multi-tier backup schedule — several whole-guest tiers (local daily + PBS weekly) reconciled into ONE quiesce window | **Both tiers due ⇒ ONE stop/start pair**, never two (two = two app outages for one night). Tiers run SEQUENTIALLY (vzdump holds a guest lock) and the app stays down until the LAST tier snapshots — resuming earlier loses app-consistency on the DR tier. Order is fast-first (agent advertises primary first) or downtime blows up. `ErrTiersUnsupported` (route 404) ⇒ pre-R-82 agent ⇒ degrade to the untargeted path and **STILL BACK UP** — never read it as "nothing due". |
 | `quiesce.failureBreaker` + `Loop.dropBackedOffTiers` / `noteTierFailure` / `noteTierSuccess` | controller/internal/quiesce/breaker.go, quiesce.go | `blocked/recordFailure/recordSuccess(target, now)`; `backoffFor(n) time.Duration` | **R-88** — a tier whose backups keep failing stops re-quiescing. Backoff 15m→30m→1h→2h→4h (cap), reset on success | **It gates the QUIESCE, not the backup** — the harm was never the failing backup, it was the app outage taken to attempt it, so backed-off tiers are dropped from the due set BEFORE any stack is stopped. **Per TARGET** — a broken offsite tier must never suppress a healthy local one (`TestBreaker_OneFailingTierDoesNotSuppressAHealthyOne`). **Never permanent** — the cap bounds the retry INTERVAL, it never stops retrying; a latched breaker is a silent backup outage, worse than the loop it replaces. **`TriggerNow` is never gated** (it already bypasses due-ness and the window gate), though a manual run still RECORDS its outcome. **`stillRunning` is NOT a failure** — a first full offsite snapshot legitimately runs for hours. State is **in-memory on purpose**: a restart forgets the backoff and re-attempts, which is the cheap direction to fail. Log the deferral ONCE when armed, never per tick. |
+| `quiesce.TierNotifier` + `Loop.SetTierNotifier` / `noteTierFailure` / `noteTierSuccess` | controller/internal/quiesce/breaker.go, quiesce.go | `BackupFailed(tier,msg,err)` / `BackupRecovered(tier,msg)`; `SetTierNotifier(n)` INIT-ONLY | **R-97a** — the whole-guest backup tier reports its outcome to the hub | A **seam, not an import** — quiesce keeps no dependency on `internal/notify` (same reason `windowStartFn` is injected). Wired by a setter because main.go builds the notifier AFTER the loop; `nil` = unprovisioned guest, not an error. **Edge-triggered:** failure fires only when the breaker ARMS (`n == 1`), never per retry — the cadence is 15m/30m/1h/2h/4h and an event per attempt is an inbox nobody reads. Recovery rides `recordSuccess`'s existing bool. **Event types are OPERATOR-ONLY** (`whole_guest_backup_failed`/`_recovered`, hub >= v0.78.0) — NOT `backup_failed`, which has a customerMessages entry AND sits in live `enabled_events`, so it would email the CUSTOMER about a backup they cannot act on. `WholeGuestBackupDetails.Tier` is load-bearing: the hub keys its per-tier cooldown on it. |
+| `quiesce.Loop.SuppressedStacks` + `markQuiesced` / `markUnquiesced` | controller/internal/quiesce/suppress.go | `() map[string]bool` (nil-safe on a nil *Loop) | **R-97b** — an app THIS controller stopped for a backup is not a fault | Consumed at the SINGLE derivation point `classifyRunStates` (which computes both the banner dead-list and the notifier Down-set — keep it one place). **Cycle-keyed, not state-based:** v0.164.0's `!= StateStopped` filter cannot see an app caught MID-RESTART (`starting`/`unhealthy`), which is how BookStack alarmed on 2026-07-27. The window (`quiesceAlarmGrace` = 180 s, derived from the deploy flow's 120 s health timeout and Mealie's 60 s start_period) **EXPIRES** — permanent suppression turns a loud false alarm into a silent real one. Open-ended while the cycle runs (a first offsite snapshot legitimately takes hours). |
 | `agentapi.BackupTiers` / `BackupDueFor` / `StartBackupFor` / `BackupStatusFor` | controller/internal/agentapi/backup_tiers.go | `(ctx[, target]) (…, error)` | The per-tier agent surface (agent >= v0.97.0) | `targetQuery("")` returns an EMPTY suffix so an untargeted call hits the pre-R-82 route byte-for-byte. `BackupTiers` maps a 404 to `ErrTiersUnsupported` — the documented ROUTE-PROBE capability signal, NOT a `featureProbes` row (the loop needs the tier LIST, not a yes/no). |
 
 ### Compose ops / stack lifecycle