- Add single and batch share endpoints with signed URL tokens
- Add public view endpoints (no auth required) for shared recommendations
- Add share button with clipboard copy to RecommendationCard
- Create SharedView page with Vynl branding and registration CTA
- Add /shared/:recId/:token public route in App.tsx
- Add shareRecommendation and getSharedRecommendation API functions
- Bandcamp: match artist+song, fall back to artist-only page
- YouTube fallback: if not on Bandcamp, link to YouTube music video search
- Fix My Playlist: AI analyzes playlist, finds outliers, suggests replacements
- User chooses recommendation count (5, 10, 15, 20)
