- Create kanzlai.notes table (polymorphic FK with CHECK constraint,
partial indexes, RLS)
- Add Note model, NoteService (ListByParent, Create, Update, Delete),
and NoteHandler with endpoints: GET/POST /api/notes, PUT/DELETE /api/notes/{id}
- Add GET /api/deadlines/{deadlineID} detail endpoint
- Add GET /api/appointments/{id} detail endpoint
- Add GET /api/case-events/{id} detail endpoint (new CaseEventHandler)
- Fix dashboard query: add case_id to upcoming_deadlines SELECT,
add id and case_id to recent_activity SELECT
- Register all new routes in router.go
