feat(telegram-calendar-bot): implement new Telegram bot for calendar integration

- Add NestJS service with Telegraf for Telegram bot functionality
- Implement commands: /today, /tomorrow, /week, /next, /calendars, /add
- Create database schema for user linking and reminder settings
- Add Calendar API client for fetching events
- Implement reminder scheduler with morning briefing support
- Add message formatters for German locale
- Include Dockerfile and CLAUDE.md documentation
- Update TELEGRAM_BOTS.md with new bot status

Commands implemented:
- /today, /tomorrow, /week - View events
- /next [n] - View next n events
- /calendars - List calendars
- /remind - Reminder settings
- /link, /unlink - Account management
- /status - Connection status

https://claude.ai/code/session_01LwmhvhKpEsvVtY1ZKhYu6f

docs/TELEGRAM_BOTS.md

@@ -9,7 +9,7 @@ Dokumentation aller Telegram-Bots im ManaCore Monorepo.
 | [telegram-stats-bot](#telegram-stats-bot) | 3300 | Analytics & Statistiken von Umami | ✅ Aktiv |
 | [telegram-ollama-bot](#telegram-ollama-bot) | 3301 | Lokale LLM-Inferenz via Ollama | ✅ Aktiv |
 | [telegram-project-doc-bot](#telegram-project-doc-bot) | 3302 | Projektdokumentation & Blogpost-Generierung | ✅ Aktiv |
-| [telegram-calendar-bot](#telegram-calendar-bot) | 3303 | Kalender-Termine & Erinnerungen | 📋 Geplant |
+| [telegram-calendar-bot](#telegram-calendar-bot) | 3303 | Kalender-Termine & Erinnerungen | 🚧 In Entwicklung |
 
 ## Gemeinsame Architektur