feat(scheduler): schedule container restart, stop, and start (#1526)

* feat(scheduler): schedule container restart, stop, and start

Add container as a scheduled-task target type so operators can automate lifecycle actions against standalone containers by node and name, with matching UI pickers, validation, execution on local and remote nodes, and tests.

* fix(scheduler): stack service matching and container picker hygiene

Backfill Service on smartFallback containers so per-service stack restarts work when container_name is set. Match services by compose label and container name in stack routes and scheduled restarts. Exclude Sencho from GET /api/containers lists. Hide the Restart Stack service picker when a stack has only one service.

* test(scheduler): scope service checkbox assertion to Services block

The create dialog also has a Delete after run checkbox. Count checkboxes only inside the Services section so CI does not include unrelated form controls.

* fix(scheduler): narrow closest() result to HTMLElement in schedule test

The service-checkbox assertion passed an Element from closest() into
within(), which requires an HTMLElement, failing tsc -b in the frontend
build and Docker build stages. Use the closest<HTMLElement>() type
argument so the value type-checks without an unsafe cast.

* fix(scheduler): hide Sencho container on remote node picker lists

Remote container lists are proxied from peer Sencho instances, so id-only self filtering missed peers on older builds. Await SelfIdentity init, match ImageID, and drop official saelix/sencho images. Apply the same heuristic in the scheduled-operations UI and when the hub fetches remote containers for scheduled runs.

* test(monitor): add missing DatabaseService mocks for scan history cleanup

* test(scheduler): add missing markStaleScansAsFailed mock

SchedulerService.tick() calls db.markStaleScansAsFailed() to sweep stale
vulnerability scans. The scheduler-service test was missing this method in
its DatabaseService mock, causing TypeError failures during test initialization.

Added mockMarkStaleScansAsFailed to hoisted mocks and DatabaseService mock
object, returning safe default of 0 scans marked as failed.

* test(compose): add missing FileSystemService mocks for getStackContent/getEnvContent

* test(containers-route): mock SelfIdentityService to prevent initialize() crash

The excludeSelfContainers() helper calls SelfIdentityService.initialize(), which tries to access DockerController. Without a proper SelfIdentityService mock, the initialize() call fails silently, causing a 500 error on GET /api/containers.

Added SelfIdentityService mock with initialize(), isOwnContainer(), and isOwnImage() methods to prevent the crash.

frontend/src/types/scheduling.ts

@@ -1,7 +1,7 @@
 export interface ScheduledTask {
   id: number;
   name: string;
-  target_type: 'stack' | 'fleet' | 'system';
+  target_type: 'stack' | 'fleet' | 'system' | 'container';
   target_id: string | null;
   node_id: number | null;
   action: 'restart' | 'snapshot' | 'prune' | 'update' | 'scan' | 'auto_backup' | 'auto_stop' | 'auto_down' | 'auto_start';