Plex cover images were fetched full-res on every surface (Slint built the raw
/library/.../thumb URL), where Tauri requests a server-transcoded thumb sized to
the render target. On a real library this made the views feel heavy and starved
the LAN bandwidth that track playback needs.
- qbz-models: ArtworkRef::PlexThumb gains a size: Option<u32>; new plex_thumb_url()
emits the Tauri-format transcode URL when Some
(/photo/:/transcode?url={enc}&width=N&height=N&minSize=1&X-Plex-Token=), raw
tokenized path when None (album/MPRIS full-res preserved). urlencoding dep added
to match encodeURIComponent. Tests extended.
- qbz-slint: each PlexThumb construction site passes its surface decode size
(grid/detail 264, queue/now-playing-item 96, now-playing bar 160, MPRIS full-res);
fetch_and_decode_ref uses plex_thumb_url.
- artwork.rs: static LazyLock<reqwest::Client> reused in fetch_cached_http instead
of reqwest::get (per-image client) — keep-alive + no fd churn (EMFILE smell).
Audio path untouched; local/Qobuz artwork unchanged.
cc