Perf/UI cover cache mainstage (#468)

* Enhance CachedImage and ArtistDetail components with improved image caching and priority handling

- Refactor CachedImage to utilize a priority system for image loading based on viewport visibility, improving performance during scrolling.
- Update useCachedUrl to accept an optional getPriority function for better cache management.
- Optimize ArtistDetail and Artists components by using useMemo for cover art URLs, reducing redundant calculations and improving rendering efficiency.
- Adjust image loading logic in CachedImage to ensure smoother transitions and avoid unnecessary fetch requests.

* perf(ui): unblock IDB cover art, stabilize mainstage rails and virtual lists

Let IndexedDB reads bypass the network concurrency slot so cached thumbnails
paint without queueing behind remote fetches; debounce disk eviction during
heavy scrolling.

Fix mainstage horizontal rails: dedupe album/song ids for React keys, widen
artwork budget overscan, avoid resetting the budget on list append, and raise
Home initial artwork budgets. CachedImage treats already-decoded images as
loaded; rail cards load cover images eagerly.

Refresh dynamic color extraction and extend virtual scrolling / scroll roots on
Albums, Artists, Playlists, and related surfaces.


Remove local agent-only commit instructions from the repository tree.

* perf(virtual): viewport-based overscan for main scroll lists

Drive TanStack Virtual overscan from measured scroll height so each list
renders about one screen of extra rows above and below the viewport for
snappier scrolling on Albums, Artists (list mode), and Tracks virtual song list.

Introduce useResizeClientHeight helpers (ID + ref) for ResizeObserver-based
clientHeight tracking.

* docs(changelog): note PR #468 UI cover cache, rails, and virtual lists

Add a coarse summary under 1.46.0 Changed for cover-art pipeline,
mainstage rails, viewport-based overscan, and library/chrome polish.

CHANGELOG.md

@@ -57,6 +57,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Heavier app **routes** are loaded **lazily** so the initial JS bundle stays smaller (`App.tsx` and related entry wiring).
 * Restored **default Vite `chunkSizeWarningLimit`** behaviour so oversized chunks are reported again during production builds (`vite.config.ts`).
 
+### UI — cover cache, mainstage rails, and smoother virtual lists
+
+**By [@cucadmuh](https://github.com/cucadmuh), PR [#468](https://github.com/Psychotoxical/psysonic/pull/468)**
+
+* **Image cache:** **Network fetches** share a small concurrency pool; **IndexedDB** hits are no longer queued behind remote downloads. **Debounced** disk eviction avoids hammering storage during fast cover scrolling. Related **shared blob URL** / hot-path fixes for thumbnails.
+* **Mainstage & rails:** **Horizontal rows** use **reworked artwork windowing** (higher initial budgets, extra slack ahead of the viewport, **no budget reset** when “load more” extends the list). **Duplicate album/song IDs** from the API are **deduped** for stable React reconciliation. **CachedImage** handles **already-decoded / cache-hit** images cleanly; rail **Album / song cards** load covers **eagerly** to reduce **blank art** while scrubbing sideways.
+* **Virtualised lists:** **Albums**, **Artists** (list mode), and the **Tracks** virtual song browser **derive** **TanStack Virtual `overscan`** from the **measured scroll viewport** (~ **one screen** of extra rows above and below) instead of a tiny fixed cushion.
+* **Library & chrome:** assorted **scroll / layout** improvements on **Artist detail**, **Playlists**, **Most played**; smaller touch-ups to **Mini player**, **Live search**, **Album header**, and **dynamic colour** extraction used by player / album surfaces.
+
 ## Fixed
 
 ### Hot cache, HTTP streaming replay, and queue source indicator