feat: notifications API, auto-jobs, calendar housekeeping fixes

Backend:
- notifications table (024 migration) — stores per-hotel notifications
- GET/PATCH/POST/DELETE /api/hotels/:slug/notifications endpoints
- createNotification() helper used by jobs + future hooks
- jobs.ts — background tasks every 10min: auto-cancel no-shows and
  auto-checkout overdue stays based on hotel_settings, broadcasts WS
  events and creates notifications for each automated action

Frontend:
- CalendarPage: handle housekeeping_done WS → update room status in
  calendar in real-time (bug fix)
- CalendarPage: when manually setting room to dirty via context menu,
  auto-create housekeeping task and broadcast via WS (bug fix)
- NotificationsContext: replaced mock data with real API integration,
  polls every 60s, syncs markRead/delete to backend
- SettingsPage booking section: auto-cancel no-show toggle + hours
  selector; auto-checkout toggle + hours selector
- api.ts: notifications API methods
- useHotelSocket: notification:new WS message type

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/hooks/useHotelSocket.ts

@@ -10,6 +10,7 @@ export type WsMessage =
   | { type: 'housekeeping_task_created'; task: Record<string, unknown> }
   | { type: 'housekeeping_updated';      task: Record<string, unknown> }
   | { type: 'housekeeping_done';         taskId: string; roomId: string; roomStatus: string }
+  | { type: 'notification:new'; notification: Record<string, unknown> }
 
 interface Options {
   slug: string