feat: emergency room closure for urgent maintenance tasks

- Backend housekeeping POST: when priority=urgent + category=maintenance + room_id
  → auto sets room status=maintenance with maintenance_from/to dates
  → closes room for emergency_close_days (default 1 day)
  → broadcasts room_updated WS event
- housekeeping-settings: add emergency_close_days column (migration 030, default 1)
- TechnicalPage: rename "Срочно" → "Экстренно!", show "🔒 Номер закрыт" badge for urgent active tasks
- HousekeepingPage plans tab: new "Экстренное закрытие номера" setting with day picker (1/2/3/5/7/14 days)
- api.ts HkSettings: add emergency_close_days field

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

src/lib/api.ts

@@ -565,6 +565,7 @@ export interface HkSettings {
   checkout_priority: string
   inspection_after_clean: boolean
   require_completion_photo?: boolean
+  emergency_close_days?: number
 }
 
 export interface HotelPayload {