Integrate ExerciseDB v2 data layer (muscleMap.ts, exercisedb.ts) to enrich
the 77 static exercises with detailed muscle targeting, similar exercises,
and expand the catalog to 254 exercises. Add interactive SVG muscle body
diagrams for both the stats page heatmap and exercise list filtering, with
split front/back views flanking the exercise list on desktop. Replace body
part dropdown with unified muscle group multi-select with pill tags.
- Add UserFavorites MongoDB model with ObjectId references
- Create authenticated API endpoints for favorites management
- Add Heart icon and FavoriteButton components with toggle functionality
- Display favorite button below recipe tags for logged-in users
- Add Favoriten navigation link (visible only when authenticated)
- Create favorites page with grid layout and search functionality
- Store favorites by MongoDB ObjectId for data integrity
Alexander