- Replaced tgbotapi with go-telegram/bot (zero-dependency, context-aware, Bot API 10.0)
- All handler methods now accept context.Context; threading ctx through all sends/edits
- Changed from function-based (NewMessage/NewEditMessageText/NewInlineKeyboardMarkup) to struct-param API (SendMessageParams/EditMessageTextParams/InlineKeyboardMarkup)
- Added colored buttons: DEL buttons in calendar use Style: 'danger' (red)
- Both polling and webhook modes preserved with new library patterns
- Context-based shutdown (signal.NotifyContext) replaces stop channel
- Add chat_id to events, settings, and days_off for per-user data
- Add proper graceful shutdown (signal handling, WaitGroup)
- Separate polling and webhook modes with goroutine management
- Add schema migration from single-user to multi-user schema
- Refactor handlers with shared actionFunc pattern (msg + callback)
- Fix schema path for Docker deployment (/app/db/schema.sql)
- Remove emoji from output text for cleaner formatting
- Show main menu with Clock In/Out, Report, Export, Remote, Day Off buttons
- Each action result includes a 'Back to Menu' button
- Handle callback queries alongside text commands
- Delete stale webhook before switching to polling
- Log i18n initialization error instead of silently ignoring it
