Niche local artists (e.g. N!GHT) whose Navidrome metadata agents have no image showed a
blank hero. Now, when Navidrome has no artist image, the hero falls back to the matched
Deezer artist's photo (Navidrome image → Deezer photo → album cover), on web + Android.
- Web (detail.js): the Deezer-photo fallback previously ran only for non-local artists;
now it runs whenever the Navidrome image is absent, local or not.
- Android: ArtistViewModel captures the matched Deezer artist's photo (deezerImage);
ArtistDetailScreen uses it as the hero fallback.
SW ns-v56.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>