LastfmAlbumPopularity.top_albums(conn, name) ranks an artist's albums by
Last.fm playcount (read-through ApiCache, 12h; errors -> []). registry
build_album_popularity returns it only when lastfm.api_key is set.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Jonathan