Add comprehensive reminder/alarm support to calendar events

- Backend: Parse VALARM components from CalDAV iCalendar data
- Backend: Add EventReminder struct with minutes_before, action, and description
- Backend: Support Display, Email, and Audio reminder types
- Backend: Parse ISO 8601 duration triggers (-PT15M, -P1D, etc.)
- Frontend: Add reminders field to CalendarEvent structure
- Frontend: Display reminders in event modal with human-readable formatting
- Frontend: Show reminder timing (15 minutes before, 1 day before) and action type
- Fix: Update Trunk.toml to properly copy CSS files to dist directory

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

test_backend_url.js

@@ -0,0 +1 @@
+console.log("Backend URL test");