Closes out the full post-launch feature backlog:
- Offline write resilience for save/delete, with automatic flush on reconnect
- Undo-after-delete via a snackbar, with a fresh-UID recreate (Nextcloud's
trashbin rejects reusing a just-deleted item's UID)
- Custom (non-preset) reminder offsets
- Search across events and tasks
- Week view alongside the existing Agenda/Month views
- BYDAY support in the Repeats picker ("every Mon/Wed/Fri"), including a
proper RRULE evaluator extension for it
- Import/export .ics via the system share sheet and file picker
- Single-occurrence recurring-event editing/deleting ("this event only" vs
"all events") via RFC 5545 RECURRENCE-ID overrides and EXDATE
A repository-wide write mutex now serializes sync against save/delete/undo,
fixing a real race where a background sync could clobber a just-written item.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>