- Extract CalendarCard to separate component (467 lines)
- Create calendarService for API and caching (156 lines)
- Add useCalendarEvents hook (96 lines)
- Create CalendarSidebar wrapper component (29 lines)
- Reduce AppShell.tsx from 1277 to 634 lines (-50%)
- Implement proper separation of concerns
- Move global cache to service layer
- Improve code maintainability and testability
