- Test extractArg parsing for all command formats
- Test isPrivateChat detection (private vs group vs supergroup)
- Test commandHelp contains all 8 commands with descriptions
- Test storageToEngine conversion fidelity
- Test New constructor wires startedAt correctly
- Add telego v1.8.0 as direct dependency for Telegram bot
- Create pkg/bot/bot.go with Bot struct, Config, New, Start, Stop
- Implement isAllowed chat authorization and per-user rate limiting
- Add command dispatch with handler stubs for all 10 commands
- Long polling lifecycle with context cancellation for graceful shutdown