v0.190.0 — the boot settle window, both gates on intent, and R-171

R-171 (a regression v0.189.0 introduced, CONFIRMED on hardware before any fix
was written). Replacing isBootOrphan's container-count term with recorded intent
made a drive-gate-stopped app read as a boot orphan: the gate stops apps with
`compose down` (zero containers) and never touches desired_state, because it is
not the customer. Observed on 9201 with the drive held unmounted — the sweep
found and started it, burned both attempts, and handed it to the dead-app alarm.
The write hazard did not materialise (the unbound mountpoint is host-root-owned
and the guest is unprivileged) but that protection is accidental and untested.
New consumer-side seam bootrecon.StartGate, fail-safe (cannot determine ⇒ do not
start), wired in main.go. The rule is not new: the API's startGatedByMissingDrive
already refuses this; the sweep bypassed it.

R-157 mechanism A. The sweep looked once at T+5s, deriving candidates from a
fleet docker was still restoring — three of six hard resets. Now a settle-then-
sweep window: sample every 5s, settled after 3 identical samples, sweep ONCE at
the end; ends on settled or a 50s budget, and the log says which. The budget is
50s because settle+budget+one retry must stay under the 90s dead-app grace — a
test rejected 60s at 95s. A window that overruns emits a LATE RECOVERY warn
rather than the grace being widened to hide it.

Widening the window made two more holders reachable, so the one gate covers all
three: an absent drive, a quiesce, and an in-flight app-data operation — reusing
quiesce.SuppressedStacks() and a new read-only AppStopGuard.HeldStacks().

R-170. shouldRecreateOnBoot now reads desired_state with the identical three-way
table; absent keeps the old hasContainers behaviour exactly. Its comment argued
for the container count and was rewritten. presentStable is untouched. The two
gates' agreement is pinned from both sides against one fixture table.

27/27 packages green; 6 red-proofs observed FAIL then restored.

REUSE.md

@@ -89,6 +89,9 @@
 | `appbackup.DBServiceNames` / `dbTypeForImage` (R-47, v0.153.0) | controller/internal/appbackup/dbservices.go | `(composePath string) ([]string, error)` | naming the compose SERVICE(s) holding a database, sorted | yaml.v3 `services:` MAP parse — **never a line scan** (immich's top-level `immich_ml_cache:` / `immich_postgres_data:` volume keys look exactly like services). `dbTypeForImage` is shared with `DiscoverDatabases`, which is what makes "a dump exists ⇒ a service can be named" hold. An error means CANNOT-TELL, never "no database" — callers refuse when a dump exists |
 | `Manager.StartStack/StopStack/RestartStack/UpdateStack` | controller/internal/stacks/manager.go | `(name string) error` | Lifecycle | Protected stacks refuse stop; all funnel through composeExec. **NOT writers of desired state (R-166)** — 14 call sites, only 2 are the customer; recording intent here would make a nightly backup indistinguishable from the customer pressing Stop. Use `SetDesiredState` at the intent point instead |
 | `Manager.SetDesiredState` / `DesiredStateOf` / `BackfillDesiredState` (R-166, v0.189.0) | controller/internal/stacks/desiredstate.go | `(name, desired string) error` / `(Stack) string` / `() int` | THE customer-intent record — `app.yaml` `desired_state`, tri-state `""`/`running`/`stopped` | **ONE OWNER: the customer's action.** Writers are the API action switch, `DeployStack`, `UpdateOptionalConfig`'s redeploy branch, and the `.fab` restore adapter — nothing else, ever. **`""` (absent) means UNKNOWN, never "running"**: every pre-v0.189.0 app.yaml reads absent, so treating it as running would start every deliberately-stopped app on upgrade. Write intent BEFORE the act and REFUSE the act if it fails (§8.2). Backfill is **running-only** — never infer `stopped` from zero containers, that inference IS the defect |
+| `Manager.DriveLive` (R-171, v0.190.0) | controller/internal/stacks/deploy.go | `(hddPath string) bool` | is an app's data drive a live mountpoint RIGHT NOW | Wraps the **same** `isMountPoint` seam the userdata belt uses (`manager.go`) — never write a second liveness check, the two would drift invisibly. The system/local path is legitimately not a mountpoint and returns true |
+| `bootrecon.StartGate` (R-171, v0.190.0) | controller/internal/bootrecon/bootrecon.go | `MayStart(stack) (bool, reason)` | THE one question the boot sweep asks before starting anything | **Fail-safe: cannot determine ⇒ return FALSE.** One seam for all three holders (absent drive · quiesce · an in-flight app-data operation) because they differ only in the reason string. Implemented in `main.go` (`bootDriveGate`) reusing `quiesce.SuppressedStacks()`, `AppStopGuard.HeldStacks()` and `Manager.DriveLive` — never re-derive any of them. Held apps go to `Result.HeldByDrive`, **never** `StillDown` (that is the dead-app alarm's bucket) |
+| the boot settle window (R-157 A, v0.190.0) | controller/cmd/controller/main.go | `bootReconcileSample` / `StableFor` / `Budget` | sample the fleet until it stops changing, then sweep ONCE | **settle + budget + one `DefaultRetryDelay` must stay under `deadAppBootGrace`** — pinned by `TestBootWindow_CommonCaseFitsInsideTheDeadAppGrace`, which is why the budget is 50 s and not 60 s. Sampling is READ-ONLY; sweeping per sample would never see a settled fleet (the sweep's own StartStack changes it). A late recovery is REPORTED (`recordLateRecovery`), never hidden by widening the grace |
 | `backup.AppStopGuard` (`Begin`/`End`/`Recover`) (R-166, v0.189.0) | controller/internal/backup/appstop_marker.go | `(opID, reason, stacks) error` / `()` / `() *AppStopRecovery` | THE crash marker for stop→work→start windows (volume dump, offbox reconstitute, `.fab` export) | Its **own** file (`appstop-state.json`), never quiesce's — one file, one writer. **A `defer` is NOT the mechanism** (Campaign 8 fault 10: SIGKILL runs no defer); the marker is. Written BEFORE the stop, cleared ONLY after a restart that succeeded; a FAILED restart deliberately KEEPS it. `Recover` RETURNS its outcome rather than notifying, because it must complete before the boot reconciler while the notifier does not exist yet |
 | `Manager.DeleteStack` / `RemoveStack` | controller/internal/stacks/delete.go | `(name, removeHDDData[, backupPaths])` | THE guarded removal paths | Orphan/protected/deploying/running checks + ProtectedHDDPaths filter before any RemoveAll |
 | `resolveContainerState` / `aggregateState` | controller/internal/stacks/manager.go | `(dockerState, dockerStatus)` / `([]ContainerInfo)` | State classification | `.State` says "running" even when unhealthy — `.Status` parse is the fix |