- Query/update watchlist artists by deezer_artist_id in config endpoint
- Return deezer_artist_id in config response and recent albums response
- Add Deezer provider badge (purple) to linked provider section
- Detect Deezer vs iTunes for provider linking using fallback source setting
- Show "X fans" instead of "Pop: 0" for Deezer artist search results
- Include followers count in match/search artist response
- Add deezer_artist_id matching to library enrichment and recent releases queries