feat(notes): rich-text editor with tiptap (task 85)

Replace plain textarea with shared tiptap editor and sanitized html rendering.

Adds interactive checklists on read surfaces and mobile overflow fixes.

docs/tasks/85-rich-text-notes.md

@@ -30,11 +30,11 @@ Journal (86) and notes need modern formatting and emoji. Notes currently overflo
 
 ## Acceptance criteria
 
-- [ ] ADR 0004 accepted with library and storage format chosen.
-- [ ] Shared editor component in tree.
-- [ ] Notes create/edit use it.
-- [ ] Formatting renders on all notes surfaces.
-- [ ] Mobile overflow fixed; E2E green.
+- [x] ADR 0004 accepted with library and storage format chosen.
+- [x] Shared editor component in tree.
+- [x] Notes create/edit use it.
+- [x] Formatting renders on all notes surfaces.
+- [x] Mobile overflow fixed; E2E green.
 
 ## Notes