- GET /onboarding offers the library's top artists (with album covers)
and genres and says whether to show it (not done and < 10 plays);
PUT /me/onboarding stores the choice or a skip (migration 00009).
- The recommender seeds the taste from it while the user has fewer than
30 scored tracks: chosen artists' tracks +1, chosen genres +0.5.
- Web: onboarding replaces the wave on the home page until done or
skipped; artist grid with covers, genre chips, at least 3 artists.
- e2e journey and the recommender DB test cover it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>