Connect ChannelsPage, FloorMapPage, SettingsPage, UsersPage to real API

- ChannelsPage: load from API, toggle/sync call real endpoints; normalize
  enabled→isEnabled, lastSyncedAt→lastSyncAt, add displayName/mappings defaults
- FloorMapPage: load rooms+bookings from API; create booking via API
- SettingsPage: load hotel via GET /api/hotels/:slug; save general section
  via PATCH (name, address, timezone, currency, check_in/out times)
- UsersPage: load users from API; create/update/delete via API;
  map backend User (name/role) → StaffUser (firstName/lastName/StaffRole)
- api.ts: add hotels.get/update, users.delete, channel normalization,
  HotelPayload/toHotelPayload
- types/index.ts: extend Hotel with phone/checkInTime/checkOutTime/optional fields;
  add User.createdAt/updatedAt
- backend/routes/hotels.ts: extend PATCH to allow address/phone/check_in_time/check_out_time
- backend/migrations/004_hotels_contacts.sql: add address/phone/check_in/out_time to hotels

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

src/types/index.ts

@@ -11,6 +11,8 @@ export interface User {
   hotelName?: string
   hotelSlug?: string
   avatarUrl?: string
+  createdAt?: string
+  updatedAt?: string
 }
 
 export interface AuthSession {
@@ -26,13 +28,17 @@ export interface Hotel {
   id: string
   name: string
   slug: string
-  address: string
+  address?: string
+  phone?: string
   timezone: string
   currency: string
+  checkInTime?: string
+  checkOutTime?: string
   logoUrl?: string
   plan: HotelPlan
-  isActive: boolean
-  roomCount: number
+  isActive?: boolean
+  roomCount?: number
+  activeBookings?: number
   createdAt: string
 }