Major UX improvements across multiple pages

Шахматка:
- Date/period picker dropdown on navigation button (choose start date + days window)
- Cancelled bookings fade out with animation after 1 second

Бронирования:
- Clickable column headers with sort asc/desc (Гость, Заезд, Выезд, Статус, Источник, Сумма)

Страница входа:
- Removed role-based account selector — just email + password
- System auto-detects role/hotel from credentials

Настройки:
- New "Бронирование" section with room assignment strategy (spread/together/sequential/manual)
- Notifications: SMTP email config + SMS provider config (SMSC, SMS.ru, МТС, etc.)

Модули:
- Added Housekeeping and Channel Manager as proper modules
- Channel Manager lists: Booking.com, Airbnb, Яндекс Путешествия, Островок, Суточно.ру, OneTwoTrip
- Housekeeping visible to all roles (including housekeeper) via module status
- Sidebar now uses module status to show/hide Уборка and Каналы

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

backend/package.json

@@ -0,0 +1,29 @@
+{
+  "name": "hotelsync-api",
+  "version": "1.0.0",
+  "description": "HotelSync PMS — REST API",
+  "main": "dist/server.js",
+  "scripts": {
+    "dev": "tsx watch src/server.ts",
+    "build": "tsc",
+    "start": "node dist/server.js"
+  },
+  "dependencies": {
+    "@fastify/cookie": "^9.4.0",
+    "@fastify/cors": "^9.0.1",
+    "@fastify/helmet": "^11.1.1",
+    "@fastify/jwt": "^8.0.1",
+    "@fastify/rate-limit": "^9.1.0",
+    "bcryptjs": "^2.4.3",
+    "fastify": "^4.28.1",
+    "ioredis": "^5.3.2",
+    "pg": "^8.12.0"
+  },
+  "devDependencies": {
+    "@types/bcryptjs": "^2.4.6",
+    "@types/node": "^20.14.0",
+    "@types/pg": "^8.11.6",
+    "tsx": "^4.15.7",
+    "typescript": "^5.4.5"
+  }
+}