feat(desktop): auto-recover in-progress desktop tasks on client lifecycle events

- reset stale in_progress tasks owned by a client on startup, offline, and lease expiry
- monitor tasks re-queue for another pick; publish tasks move to unknown for manual reconcile
- send startup=true flag on first heartbeat so the server can trigger recovery
- finalize the linked desktop task when a phase2 monitor callback arrives via desktop_tasks path
- short-circuit the desktop monitor attempt write after the callback already finalized it

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/internal/tenant/transport/desktop_client_handler.go

@@ -15,11 +15,17 @@ type DesktopClientHandler struct {
 }
 
 func NewDesktopClientHandler(a *bootstrap.App) *DesktopClientHandler {
+	taskSvc := app.NewDesktopTaskService(
+		a.DB,
+		a.MonitoringDB,
+		a.RabbitMQ,
+		a.Logger,
+	).WithCache(a.Cache)
 	return &DesktopClientHandler{
 		svc: app.NewDesktopClientService(
 			repository.NewDesktopClientRepository(a.DB),
 			a.Redis,
-		),
+		).WithTaskService(taskSvc),
 	}
 }