feat: auto-heal policies for unhealthy containers (#671)

* feat(db): add auto_heal_policies and auto_heal_history schema and CRUD

Adds two new SQLite tables (auto_heal_policies, auto_heal_history) to
DatabaseService.initSchema() and exposes CRUD methods: getAutoHealPolicies,
getAutoHealPolicy, addAutoHealPolicy, updateAutoHealPolicy,
deleteAutoHealPolicy, recordAutoHealHistory, getAutoHealHistory,
incrementConsecutiveFailures, resetConsecutiveFailures, setPolicyEnabled.
Also adds AutoHealPolicy and AutoHealHistoryEntry TypeScript interfaces.

* feat(events): track health-status duration and expose state accessors

- Add healthStatus and unhealthySince fields to InternalContainerState
- onHealthStatus now records unhealthySince timestamp on first transition
  to unhealthy, and clears it when the container recovers or restarts
- onStart resets both fields so a restarted container begins from 'starting'
- Add listContainerStates() and getContainerState() public accessors for
  use by the upcoming AutoHealService evaluator

* fix(auto-heal): key allowlist in updateAutoHealPolicy, cascade delete, extract ContainerHealthSnapshot

* feat: add AutoHealService evaluator singleton

Polls every 30 s, matches containers to enabled policies via Compose
labels, and restarts containers that have been unhealthy beyond the
configured threshold. Enforces cooldown, per-hour rate cap, and
recent-user-action suppression; auto-disables policies after repeated
consecutive failures. Also adds DockerEventManager.getService() accessor
required by the evaluator.

* fix(auto-heal): prune stale restartTimestamps, guard undefined policy id

- Prune restartTimestamps entries for containers no longer running after
  each container list fetch, preventing unbounded map growth from dead
  container IDs.
- Guard against policies with undefined id at the start of the per-policy
  loop; warn and skip rather than proceed with a non-null assertion.
- Extract handleAutoDisable private helper to bring executeHeal under 30
  lines and isolate the auto-disable side-effect sequence.
- Move ContainerInfo type to module scope.

* feat: add auto-heal API routes and wire AutoHealService lifecycle

Registers five REST endpoints under /api/auto-heal/policies (list, create,
patch, delete, history) with requirePaid + requireAdmin guards and Zod
validation. Wires AutoHealService.start()/stop() into the server startup
and graceful-shutdown blocks alongside MonitorService.

* test: add AutoHealService and DatabaseService auto-heal unit tests

- 15 unit tests for AutoHealService.shouldHeal covering all decision branches
  (healthy state, duration threshold, user-action suppression, cooldown,
  rate limiting, and correct skipReason values)
- 13 integration tests for DatabaseService auto-heal CRUD: policy round-trip,
  stack-name filter, partial update, cascade delete, history ordering/limit,
  consecutive failure counters, and setPolicyEnabled toggle

* fix: log AutoHealService shutdown errors consistently

* fix(api): requireAdmin-first guard order and try/catch on auto-heal routes

* feat(ui): add StackAutoHealSheet component

* feat(ui): add Auto-Heal context menu item to EditorLayout

* fix(ui): StackAutoHealSheet label, token, a11y, and useEffect fixes

- Rename 'All services in stack' to 'All services' in combobox options and placeholder
- Replace text-green-600 with text-success design token in actionColorClass
- Add htmlFor/id pairs to all four numeric form inputs for accessibility
- Inline fetch logic into useEffect, removing stale closure risk and eslint-disable comment
- Remove now-unused fetchPolicies and fetchServices standalone functions
- Update 'Auto-disable after' label to 'Auto-disable after (failures)' for clarity
- Add toast.error in policy fetch failure path; services fetch silently skips as before

* docs: add auto-heal-policies feature documentation

* test(e2e): add auto-heal policies CRUD spec

* fix(docs): correct auto-heal-policies nav position in docs.json

backend/src/services/DockerEventService.ts

@@ -24,6 +24,16 @@ import { getErrorMessage } from '../utils/errors';
  * See docs/features/alerts-notifications.mdx for user-facing behaviour.
  */
 
+/** Snapshot of a single container's health tracking state, exposed to AutoHealService. */
+export interface ContainerHealthSnapshot {
+    id: string;
+    name?: string;
+    stackName?: string;
+    healthStatus?: 'healthy' | 'unhealthy' | 'starting';
+    unhealthySince?: number;
+    lastKillAt?: number;
+}
+
 /** Grace window after a `die` before classifying, to absorb out-of-order kill events. */
 const DIE_GRACE_WINDOW_MS = 500;
 
@@ -61,6 +71,8 @@ interface InternalContainerState extends ContainerLifecycleState {
     stackName?: string;
     lastCrashAlertAt?: number;
     lastActivityAt: number;
+    healthStatus?: 'healthy' | 'unhealthy' | 'starting';
+    unhealthySince?: number;
 }
 
 interface DockerEventPayload {
@@ -400,16 +412,29 @@ export class DockerEventService {
     }
 
     private onHealthStatus(id: string, action: string, event: DockerEventPayload): void {
-        if (!action.includes('unhealthy')) return;
         const state = this.getOrCreateState(id, event);
         state.lastActivityAt = Date.now();
-        if (!this.isCrashAlertsEnabled()) return;
-        const name = state.name ?? id.slice(0, 12);
-        const stackName = state.stackName;
-        void this.emitError(
-            `Healthcheck failed: ${name} is unhealthy.`,
-            stackName,
-        );
+
+        if (action.includes('unhealthy')) {
+            if (state.healthStatus !== 'unhealthy') {
+                state.unhealthySince = Date.now();
+            }
+            state.healthStatus = 'unhealthy';
+            if (!this.isCrashAlertsEnabled()) return;
+            const name = state.name ?? id.slice(0, 12);
+            const stackName = state.stackName;
+            void this.emitError(
+                `Healthcheck failed: ${name} is unhealthy.`,
+                stackName,
+            );
+        } else {
+            state.unhealthySince = undefined;
+            if (action.includes('starting')) {
+                state.healthStatus = 'starting';
+            } else {
+                state.healthStatus = 'healthy';
+            }
+        }
     }
 
     private onStart(id: string): void {
@@ -419,6 +444,8 @@ export class DockerEventService {
         state.lastKillAt = undefined;
         state.oomPending = undefined;
         state.lastCrashAlertAt = undefined;
+        state.unhealthySince = undefined;
+        state.healthStatus = 'starting';
         state.lastActivityAt = Date.now();
     }
 
@@ -649,4 +676,32 @@ export class DockerEventService {
             trackedContainers: this.containerState.size,
         };
     }
+
+    // ========================================================================
+    // Container state accessors (used by AutoHealService)
+    // ========================================================================
+
+    public listContainerStates(): ContainerHealthSnapshot[] {
+        return Array.from(this.containerState.entries()).map(([id, s]) => ({
+            id,
+            name: s.name,
+            stackName: s.stackName,
+            healthStatus: s.healthStatus,
+            unhealthySince: s.unhealthySince,
+            lastKillAt: s.lastKillAt,
+        }));
+    }
+
+    public getContainerState(id: string): ContainerHealthSnapshot | undefined {
+        const s = this.containerState.get(id);
+        if (!s) return undefined;
+        return {
+            id,
+            name: s.name,
+            stackName: s.stackName,
+            healthStatus: s.healthStatus,
+            unhealthySince: s.unhealthySince,
+            lastKillAt: s.lastKillAt,
+        };
+    }
 }