Out-of-library suggestion artists (artist_similarity_unmatched rows)
have no local art row, so the Discover card always showed a
placeholder. Resolve art on-demand from Lidarr's artist lookup,
matched by MBID (foreignArtistId == candidate_mbid), and pass the
remote image URL straight through — no caching (a suggestion may
never be viewed; the browser fetches the URL directly).
- suggestionView gains image_url (omitempty); handler resolves it via
bounded-concurrency Lidarr LookupArtist, best-effort, never fails
the request.
- Lidarr is the sole source: disabled / unreachable / no-match →
empty → existing placeholder. (No inline TheAudioDB fallback — it's
externally rate-limited and there's no cache to amortize it.)
- web: ArtistSuggestion.image_url?; SuggestionFeed passes it to
DiscoverResultCard (already supports imageUrl).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen