feat(13-02): add library filter dropdown and wire all views to respect active filter

- Add selectedLibraryId state + ByLibrary conditional calls to library-store
- Add library filter pass-through methods to library-controller
- Create library-filter dropdown component in top bar
- Wire genre-details, cover-grid, artists-view, genres-view to use ByLibrary queries
- Update album-selection helper to respect library filter
- Regenerate Wails bindings for new ByLibrary methods
- Search remains client-side (automatically filtered by loaded data)
- Playlists remain unfiltered (use separate playlist store)

frontend/src/components/artists-view/artists-view.ts

@@ -13,6 +13,8 @@ import { grid } from '@lit-labs/virtualizer/layouts/grid.js';
 import {
     GetAlbumsByArtist,
     GetAlbumTracks,
+    GetAlbumsByArtistByLibrary,
+    GetAlbumTracksByLibrary,
 } from '@go/library/Library';
 import { library } from '@go/models';
 import { LibraryController } from '@store/controllers/library-controller';
@@ -927,20 +929,31 @@ export class ArtistsView
     /**
      * Fetches all file paths for an artist by
      * loading their albums, then each album's
-     * tracks.
+     * tracks.  Respects the active library filter.
      */
     private async getArtistFilePaths(
         artist: library.Artist,
     ): Promise<string[]> {
         try {
-            const albums =
-                await GetAlbumsByArtist(artist.ID);
+            const libId =
+                this.libraryCtrl.selectedLibraryId;
+
+            const albums = libId !== null
+                ? await GetAlbumsByArtistByLibrary(
+                      artist.ID,
+                      libId,
+                  )
+                : await GetAlbumsByArtist(artist.ID);
 
             const allPaths: string[] = [];
 
             for (const album of albums) {
-                const tracks =
-                    await GetAlbumTracks(album.ID);
+                const tracks = libId !== null
+                    ? await GetAlbumTracksByLibrary(
+                          album.ID,
+                          libId,
+                      )
+                    : await GetAlbumTracks(album.ID);
 
                 for (const t of tracks) {
                     allPaths.push(t.FilePath);