Critical fixes:
- [C1] _reactivate_recurring_todos now uses flush + with_for_update
instead of mid-request commit; get_todos commits the full transaction
- [C2] recurrence_rule validated via Literal["daily","weekly","monthly"]
in Pydantic schemas (rejects invalid values with 422)
Warnings fixed:
- [W3] Clear due_time when due_date is set to null in update endpoint
Suggestions applied:
- [S2] Wrap filteredTodos in useMemo for consistent memoization
- [S6] Add aria-labels to edit/delete icon buttons
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>