fix(home): scope Because you listened rail to sidebar library (#964)

* fix(home): scope Because you listened rail to sidebar library

Similar-artist album picks used getArtist without library filtering;
session cache also ignored musicLibraryFilterVersion. Filter picks to
the scoped album set and key cache/reserve by filter version.

* docs(changelog): credit zunoz on Psysonic Discord for PR #964

* test: satisfy SubsonicAlbum required fields in new unit tests

Fix tsc --noEmit CI: songCount and duration are required on SubsonicAlbum.

src/api/subsonicLibrary.ts

@@ -150,6 +150,29 @@ export async function filterSongsToActiveLibrary(songs: SubsonicSong[]): Promise
   return filterSongsToServerLibrary(songs, activeServerId);
 }
 
+/** Client-side album scope filter — same album-id set as {@link filterSongsToServerLibrary}. */
+export function filterAlbumsByScopedAlbumIds(
+  albums: SubsonicAlbum[],
+  allowed: Set<string> | null,
+): SubsonicAlbum[] {
+  if (!allowed || allowed.size === 0) return albums;
+  return albums.filter(a => allowed.has(a.id));
+}
+
+export async function filterAlbumsToServerLibrary(
+  albums: SubsonicAlbum[],
+  serverId: string,
+): Promise<SubsonicAlbum[]> {
+  const allowed = await albumIdsInLibraryScope(serverId);
+  return filterAlbumsByScopedAlbumIds(albums, allowed);
+}
+
+export async function filterAlbumsToActiveLibrary(albums: SubsonicAlbum[]): Promise<SubsonicAlbum[]> {
+  const { activeServerId } = useAuthStore.getState();
+  if (!activeServerId) return albums;
+  return filterAlbumsToServerLibrary(albums, activeServerId);
+}
+
 /** When scoped to one library, ask the server for more similar tracks — many will be filtered out client-side. */
 export function similarSongsRequestCount(desired: number): number {
   const { activeServerId, musicLibraryFilterByServer } = useAuthStore.getState();

src/api/subsonicLibraryAlbumScope.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, it } from 'vitest';
+import type { SubsonicAlbum } from './subsonicTypes';
+import { filterAlbumsByScopedAlbumIds } from './subsonicLibrary';
+
+const album = (id: string): SubsonicAlbum => ({
+  id,
+  name: id,
+  artist: 'a',
+  artistId: '1',
+  songCount: 1,
+  duration: 1,
+});
+
+describe('filterAlbumsByScopedAlbumIds', () => {
+  it('returns all albums when scope is unset', () => {
+    const albums = [album('a'), album('b')];
+    expect(filterAlbumsByScopedAlbumIds(albums, null)).toEqual(albums);
+  });
+
+  it('keeps only albums in the scoped id set', () => {
+    const albums = [album('a'), album('b'), album('c')];
+    expect(filterAlbumsByScopedAlbumIds(albums, new Set(['a', 'c']))).toEqual([album('a'), album('c')]);
+  });
+});