8caa1f45ae
- Database: Add external_calendars table with user relationships and CRUD operations - Backend: Implement REST API endpoints for external calendar management and ICS fetching - Frontend: Add external calendar modal, sidebar section with visibility toggles - Calendar integration: Merge external events with regular events in unified view - ICS parsing: Support multiple datetime formats, recurring events, and timezone handling - Authentication: Integrate with existing JWT token system for user-specific calendars - UI: Visual distinction with 📅 indicator and separate management section 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>