Implements GitHub issue #139 - allows users to create and manage custom
event types beyond the default presets (wedding, birthday, corporate, other).
Backend:
- Add event_types table migration with default system types
- Create eventTypeService for CRUD operations with legacy fallback
- Add adminEventTypes routes with full REST API
- Update event validation to use dynamic event types
- Update slug generation to use custom slug_prefix
Frontend:
- Add EventTypesPage with full CRUD admin interface
- Add eventTypes.service.ts API client
- Update CreateEventPage to fetch types dynamically
- Add Event Types navigation in admin sidebar
- Add i18n translations (EN/DE)
Backward compatible: existing galleries continue to work, legacy types
accepted even if database is empty via fallback mechanisms.