A pasted Deezer artist link (or any Deezer-source artist click) opened the
wrong artist's header: deezer_id 525046 is stamped on 4 library rows (Kendrick
+ 3 others — an enrichment-corruption bug), and the library-upgrade lookup did
WHERE deezer_id=? LIMIT 1, grabbing an arbitrary row (Jorja Smith) while the
discography loaded fresh from Deezer (Kendrick) — a Frankenstein page.
find_library_artist_for_source now detects when a source id maps to >1 library
artist and refuses to guess: it skips the id-based upgrade (still allowing the
name fallback), so the caller renders the source artist directly — landing on
the correct artist. Unique ids are unaffected (no regression).
The underlying enrichment bug that writes one source id onto multiple artists
is separate and still worth a follow-up.