- Add left sidebar filter panel to MixedView and GamesView with name search and tag toggles; only shows tags/categories used in the current library; AND logic when multiple tags are selected - Add GET /api/tags/library-assignments endpoint returning all tag assignments for a library keyed by mediaKey - Add getTagAssignmentsForLibrary() and getTagsSortedByUsage() to tags lib - Support ?sort=usage on GET /api/tags/items to order by assignment count - Tag selector: per-category search, top-25-by-usage display, inline add tag (auto-assigned to current item) and add category flows - Tag selector: group assigned tags by category into nested pills - Fix nested <button> hydration error in EntryTile (outer element is now a div with role="button") - Keep filter panel assignments in sync when tags are toggled or created Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>