controller v0.239.0: any backup tier lets an app update (R-475)

Operator ruling 2026-09-13. The update precondition walks Tier 2, Tier 1
(own recovery unit, "helyi") and Tier 3 (off-site, 15 s bound; unreachable
counts as absent with a WARN) and leans on the first FRESH copy; the
backup_max_age rule applies to whichever tier is chosen. No copy anywhere:
back up first. Refused only when nothing exists and no backup can be taken.
RunAppBackupNow tolerates a Tier-2 failure (WARN) and marks the captured
unit proven current. The hold names the tier (második meghajtó / saját
meghajtó / távoli mentés) and the date; pre-v0.239.0 holds keep their text.
A successful off-site restore now lifts an update hold. The backups page
still uses Tier2UnitRestorePoint unchanged.

Scenarios G-M tested; red-proofs M, L, the tail and the off-site clear in
felhom.eu documentation/audits/rulings-r472-r475-2026-09-13/.

REUSE.md

@@ -122,8 +122,9 @@
 | `Manager.recordInstalledImages` (v0.233.0) | controller/internal/stacks/installed.go | `(name, stackDir string, env []string)` | writing down what each compose SERVICE is ACTUALLY running, into `app.yaml.installed_images` | Called after a successful compose up from `StartStack`/`RestartStack`/`UpdateStack`/`runComposeDeploy`. **Reads the CONTAINER, never `docker-compose.yml`** — that file is the value the syncer has already moved (spike §3: 25 minutes of disagreement). **A failed write NEVER refuses the action** — the deliberate OPPOSITE of `SetDesiredState`: intent refused, observation logged at ERROR. **NOT from `StartStackServices`** (the R-47 DB-only window would overwrite a complete record with a partial one). Skips the write when ref+digest are unchanged, and carries `at` forward so it means "running since". Its OWN seam (`installedExecFn`) with a **context + 30 s timeout** — the two existing exec helpers have neither |
 | `Manager.SetPin` / `AdoptPins` / `RenderPlanFor` / `AppliedComposePath` (v0.235.0) | controller/internal/stacks/pin.go | `SetPin(name, stackDir, pin, composeSrc) error` | THE version freeze — `app.yaml.pinned_images` + the stored `applied-compose.yml` | **`PinnedImages` is INTENT, `InstalledImages` is an OBSERVATION — never feed one from the other** (the R-166 category error, one field over). Four writers only: deploy, the guarded update (via `advancePinToCatalog`, which advances the pin and re-renders BEFORE the pull, and REFUSES the update if the pin cannot be written; a failed pull puts the pin BACK via `SetPin`), the restore adapter (this is what closes R-441), and `AdoptPins`. `AdoptPins` reuses `observationCoversTemplate` — do NOT write a second completeness rule — and skips loudly rather than inventing a pin. Absent pin = pre-v0.235.0 behaviour |
 | `Manager.UpdatePreflight` / `StartGuardedUpdate` / `RecoverUpdates` / `ResumeInterruptedUpdates` (v0.237.0) | controller/internal/stacks/update.go | `UpdatePreflight(name) *UpdateRefusal`; `StartGuardedUpdate(name) error` | THE update — refusals, then a 202 job with phases on `Stack.Updating/UpdatePhase/UpdateError` | **Never report an update complete before health is known (R-443).** Every cheap refusal runs BEFORE the intent write. Safety dump BEFORE the pin moves; pin BEFORE pull; pull failure → pin back; health failure → stop + HOLD, pin stays. Journal-before-mutate (`update-journal.json`); `RecoverUpdates` MUST run before the boot sweep and `ResumeInterruptedUpdates` AFTER `SetUpdateGuards`. Seams: `updateComposeFn`, `updateHealthFn`, `updateMemoryFn`, `updateDiskFreeFn`, `updateNowFn` (R-457: the age check and the test read ONE clock). Unwired guards ⇒ every update refused |
-| `stacks.UpdateGuards` + `updateGuardsAdapter` (v0.237.0) | controller/internal/stacks/update.go, controller/cmd/controller/main.go | `HoldFor`, `Busy`, `RestorePoint`, `BackupNow`, `SafetyDump`, `HoldAfterFailedUpdate` | the ONLY bridge from the update job to the backup side (stacks cannot import backup) | Wired by `stackMgr.SetUpdateGuards` — pinned by `TestSlice4_UpdateGuardsAreWiredAtStartup`. Add a guard HERE, never by importing backup into stacks |
-| `backup.Manager.Tier2UnitRestorePoint` + `Tier2RestorePoint.ProvenCopyTime` (v0.237.0) | controller/internal/backup/update_guard.go | `(stack) (Tier2RestorePoint, error)` | "can this app be restored from Tier 2, and from when" — the predicate that gates BOTH the „Teljes visszaállítás" action and an update | **ONE predicate, two callers** (extracted from `buildAppBackupRows`, not copied). `CopyDate` is what the page NAMES (the package date, R-403); `ProvenCopyTime` is how OLD the data is — the last successful copy, because the manifest's `created_at` moves only when the DEFINITION changes (measured: a fresh dump under a 22-h-older manifest). Do not age a copy by `CopyDate` |
+| `stacks.UpdateGuards` + `updateGuardsAdapter` (v0.237.0; tiers v0.239.0) | controller/internal/stacks/update.go, controller/cmd/controller/main.go | `HoldFor`, `Busy`, `RestorePoints`, `CanBackUp`, `BackupNow`, `SafetyDump`, `HoldAfterFailedUpdate` | the ONLY bridge from the update job to the backup side (stacks cannot import backup) | Wired by `stackMgr.SetUpdateGuards` — pinned by `TestSlice4_UpdateGuardsAreWiredAtStartup`. Add a guard HERE, never by importing backup into stacks |
+| `backup.Manager.Tier2UnitRestorePoint` + `Tier2RestorePoint.ProvenCopyTime` (v0.237.0) | controller/internal/backup/update_guard.go | `(stack) (Tier2RestorePoint, error)` | "can this app be restored from Tier 2, and from when" — the predicate that gates BOTH the „Teljes visszaállítás" action and an update | **ONE predicate, two callers** (extracted from `buildAppBackupRows`, not copied). `CopyDate` is what the page NAMES (the package date, R-403); `ProvenCopyTime` is how OLD the data is — the last successful copy, because the manifest's `created_at` moves only when the DEFINITION changes (measured: a fresh dump under a 22-h-older manifest). Do not age a copy by `CopyDate`. **Since v0.239.0 the UPDATE no longer calls it directly** — it goes through `UpdateRestorePoints` (next row); the page still does |
+| `backup.Manager.UpdateRestorePoints` + `CanBackUpApp` (v0.239.0, R-475) | controller/internal/backup/update_guard.go | `(ctx, stack, accept func(UpdateTierPoint) bool) (UpdateTierPoint, bool, []UpdateTierPoint)` | "which backup can this update lean on" — walks Tier 2, 1, 3 and returns the first copy `accept` admits | **The age rule lives in the caller's `accept`** (stacks' `freshRestorePoint`), so it is ONE rule for every tier. Stops at the first accepted copy, so Tier 3 (restic, 15 s bound, unreachable = absent + WARN) is reached only when needed. Seams: `updateTier2PointFn`, `updateTier1PointsFn`, `updateOffsiteInvFn`. Tier numbers are pinned equal across stacks/backup by `TestR475_TierConstantsAgree` |
 | `backup.Manager.HoldAfterFailedUpdate` / `RunAppBackupNow` / `WriteUpdateSafetyDump` / `UpdateBusy` (v0.237.0) | controller/internal/backup/update_guard.go | see file | the update's hold, per-app backup-now, safety dump, busy check | The hold is `settings.RestoreHold` with `Reason: update_failed` — SAME store and gate as R-379, never a second map. `RunAppBackupNow` composes the nightly legs for ONE app (admission, DB dump, volume dump, capture, Tier-2) — do not write a second backup orchestration. A successful unit restore lifts an UPDATE hold only. **`isHeld` is ALSO true while a guarded update is moving the app (`SetUpdatingCheck`, v0.238.1)** — found live: the periodic capture overwrote a primary unit during a health wait |
 | `stacks.Manager.memoryVerdict` (v0.237.0) | controller/internal/stacks/deploy.go | `(newReq, newLimit, releasedReq, releasedLimit int) (refusal, warning string)` | the deploy's memory check, shared with the update | An update RELEASES the app's current request first. Deploy passes `0, 0` and is byte-identical in wording and log line |
 | `Syncer.SetRenderPlanFn` + `renderSource` (v0.235.0) | controller/internal/sync/sync.go | `func(appName string) stacks.RenderPlan` | the catalog render table | **NIL-SAFE: no seam = copy verbatim = the old product.** Catalog images == pin → verbatim (fixes flow + self-healing, both deliberately kept); differ → the WHOLE stored definition, **never a ref substitution into a newer template** (`wger 2.6`). `.felhom.yml` always verbatim (R-458). The syncer must NEVER read app.yaml. Re-reads the applied file before writing it — a test caught it writing an empty compose over a live app |