- Add DB index on (owner_id, jop_type, jop_parent_id, jop_updated_time DESC)
- New folderNoteCountsByUserId query: GROUP BY folder, no row data fetched
- New noteHeadersByFolder query: paginated per folder (LIMIT 100)
- navData() now fetches only folders + counts (no note rows on page load)
- navigationFragment: lazy mode renders empty note lists, lazy-loaded on expand
- toggleNavFolder / initNavPanel: htmx fetch on first expand, data-loaded guard
- Add /fragments/folder-notes endpoint for lazy per-folder note pages
- Add folderNotesPageFragment with Load more button for pagination
- Mobile: folders use counts Map, notes use paginated noteHeadersByFolder
- Tests: 129/129 passing
