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/lib/api.ts

@@ -419,6 +419,21 @@ export const api = {
       req<{ count: number }>('POST', `/api/hotels/${slug}/rate-overrides/bulk`, { overrides }),
   },
 
+  // ── Notifications ─────────────────────────────────────────────────────────
+  notifications: {
+    list: (slug: string) =>
+      req<Record<string, unknown>[]>('GET', `/api/hotels/${slug}/notifications`),
+
+    markRead: (slug: string, id: string) =>
+      req<Record<string, unknown>>('PATCH', `/api/hotels/${slug}/notifications/${id}`),
+
+    markAllRead: (slug: string) =>
+      req<{ ok: boolean }>('POST', `/api/hotels/${slug}/notifications/read-all`),
+
+    delete: (slug: string, id: string) =>
+      req<void>('DELETE', `/api/hotels/${slug}/notifications/${id}`),
+  },
+
   // ── Rate Periods ─────────────────────────────────────────────────────────
   ratePeriods: {
     list: (slug: string) =>