- Empty day view now shows Add IN / Add OUT buttons
- Day view with events also shows Add IN / Add OUT below existing events
- Hour picker → minute picker (15-min intervals) → event creation flow
- Back button returns to the day view
- 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