Portfolio: add filtering, URL sharing, and improved tag input
- Add category filters with dynamic counts that reduce as filters
applied
- Add ?filter[category]=value URL params for filterable links
- Add ?img= timestamp param that bypasses filters to show specific image
- Update URL when opening/navigating/closing modal for shareable links
- Backend: add /api/portfolio/filters endpoint with filter logic
- Backend: add timestamp lookup fallback for GetImage endpoint
Frontend:
- Portfolio page: filter dropdowns, keyboard nav, mobile improvements
- ImageUpload: live tag suggestions from API, arrow/Tab navigation,
confirmation modal before upload, mobile-optimized touch targets
- Add scrollbar-hide utility and fix filter dropdown overflow
- Move Clear all button, add vertical separator on desktop