feat(metadata): the clients take a client, an address and a key from their caller

docs/features/integrations.md

@@ -39,7 +39,7 @@ The frontend helper `lib/tauri/artwork.ts::resolveRemoteImage` prefers the local
 
 ### Read-only (artist bios)
 
-`artist.getInfo` for biographies, called from `enrich_artist_deezer` after the Deezer pass. Cached in the same `metadata_artist` row with the same 30-day TTL. **Optional**: requires a user-supplied API key in `app_setting['lastfm_api_key']`. Without it, bios are skipped silently and the UI shows local data.
+`artist.getInfo` for biographies, called from `enrich_artist_deezer` after the Deezer pass. Cached in the same `metadata_artist` row with the same 30-day TTL. **Optional**: requires a user-supplied API key in `app_setting['lastfm_api_key']`. Without it, bios are skipped silently and the UI shows local data. Only Last.fm's error 6 ("artist not found") reads as an empty answer; any other code — a refused key, a spent quota — is an `Err`, so it is retried rather than cached as an artist with no biography.
 
 **Collapse toggle (issue #422).** A long bio pushes the discography off the artist page, so the bio block carries an inline Show/Hide chevron ([`ArtistDetailView`](../../src/components/views/ArtistDetailView.tsx) + [`useArtistBioCollapsed`](../../src/hooks/useArtistBioCollapsed.ts)). The preference is **global per-profile** (`profile_setting['artist.bio_collapsed']`, default shown), not per-artist and not in Settings — toggling on any artist page is remembered across every artist. Distinct from the existing "read more/less" which only swaps the short/full bio text; collapse hides the whole block so the tracklist moves up.
 

docs/features/library.md

@@ -290,7 +290,7 @@ All three commands emit **`artist:updated`** with the artist id. Without it only
 
 Everything above carries the **square** artist photo. The [artist hero](ui.md#artist-hero) needs a **wide** one, and the only source in the stack that has one is TheAudioDB (issue #482).
 
-[`metadata::theaudiodb`](../../src-tauri/crates/core/src/metadata/theaudiodb.rs) already queried `search.php` for multi-language bios; the same response carries `strArtistFanart` (+ `2/3/4`), `strArtistWideThumb` and `strArtistBanner`. `TheAudioDbClient::artist_info` returns bio **and** `fanart_urls` from one lookup. It returns `Some` for any name match even with neither bio nor fanart, so the caller can cache the "looked, nothing there" outcome.
+[`metadata::theaudiodb`](../../src-tauri/crates/core/src/metadata/theaudiodb.rs) already queried `search.php` for multi-language bios; the same response carries `strArtistFanart` (+ `2/3/4`), `strArtistWideThumb` and `strArtistBanner`. `TheAudioDbClient::artist_info` returns bio **and** `fanart_urls` from one lookup. It returns `Some` for any name match even with neither bio nor fanart, so the caller can cache the "looked, nothing there" outcome; a failure status is an `Err`, never that outcome.
 
 **All four fanarts come back, and the strips no longer do** (issue #693). The client used to fall back to `strArtistWideThumb` and `strArtistBanner` when an artist had no fanart; both are **1000×185** strips by TheAudioDB's own spec, and the hero they were feeding is routinely wider than 1000 px and far taller than 185 px relative to its width — so they arrived upscaled and cropped to a sliver, which is what "the backdrop is blurry" looked like. They are not deserialized at all now; an artist with no fanart falls through to the blurred-photo tier, which is honest about being an ambient colour field rather than a picture. The fanarts themselves are kept **all four**, because they differ enormously in framing and the picker below lets the user choose.