feat: Add Telegram bot with group support

- Full Telegram bot implementation for Lightning Jackpot
- Commands: /start, /buy, /tickets, /wins, /address, /jackpot, /help
- Lightning invoice generation with QR codes
- Payment polling and confirmation notifications
- User state management (Redis/in-memory fallback)
- Group support with admin settings panel
- Configurable draw announcements and reminders
- Centralized messages for easy i18n
- Docker configuration included

telegram_bot/env.example

@@ -0,0 +1,22 @@
+# Telegram Bot Configuration
+TELEGRAM_BOT_TOKEN=your_telegram_bot_token_here
+
+# Backend API Configuration
+API_BASE_URL=http://localhost:3000
+
+# Frontend URL (for generating ticket links)
+FRONTEND_BASE_URL=http://localhost:3001
+
+# Redis Configuration (optional - falls back to in-memory if not set)
+REDIS_URL=redis://localhost:6379
+
+# Bot Configuration
+MAX_TICKETS_PER_PURCHASE=100
+PAYMENT_POLL_INTERVAL_MS=5000
+PAYMENT_POLL_TIMEOUT_MS=900000
+INVOICE_EXPIRY_MINUTES=15
+
+# Logging
+LOG_LEVEL=info
+NODE_ENV=development
+