- Add long date format display (Monday, April 23, 2024)
- Use 24h time format
- Show/hide time fields based on all-day state
- Remove auto-update of end date when start date changes
- Fix validation for all-day events
- Auto-expand for multi-day events
- Set default time when toggling off all-day from all-day slot
- Hide end date by default; reveal via '...' button in both modes
- Keep state/validation/API logic unchanged
- Normalize labels to use MUI TextField labels across modes
- Align button with fields; constrain widths for expanded mode