fix(statistics): scope genre insights to selected music library

getGenres() ignores musicFolderId. Derive genre counts from the same
paginated getAlbumList('newest') scan used for playtime and totals,
using each album's genre and songCount.

src/pages/Statistics.tsx

@@ -1,5 +1,5 @@
 import React, { useEffect, useState } from 'react';
-import { getAlbumList, getArtists, getGenres, getRandomSongs, SubsonicAlbum, SubsonicGenre } from '../api/subsonic';
+import { getAlbumList, getArtists, getRandomSongs, SubsonicAlbum, SubsonicGenre } from '../api/subsonic';
 import AlbumRow from '../components/AlbumRow';
 import { useTranslation } from 'react-i18next';
 import { useAuthStore } from '../store/authStore';
@@ -64,30 +64,29 @@ export default function Statistics() {
       getAlbumList('frequent', 12).catch(() => []),
       getAlbumList('highest', 12).catch(() => []),
       getArtists().catch(() => []),
-      getGenres().catch(() => []),
-    ]).then(([rc, fr, hi, a, g]) => {
+    ]).then(([rc, fr, hi, a]) => {
       setRecent(rc);
       setFrequent(fr);
       setHighest(hi);
       setArtistCount(a.length);
-      // Album/song totals come from paginated getAlbumList (see playtime effect) — getGenres is not musicFolder-scoped.
-      const sorted = [...g].sort((a, b) => b.songCount - a.songCount);
-      setGenres(sorted);
       setLoading(false);
     }).catch(() => setLoading(false));
   }, [musicLibraryFilterVersion]);
 
-  // Background: playtime + album/song counts (same paginated list as library filter; caps at 5000 albums)
+  // Background: playtime, album/song counts, genre insights (paginated getAlbumList — respects library filter; caps at 5000 albums)
   useEffect(() => {
     let cancelled = false;
     setTotalPlaytime(null);
     setTotalAlbums(null);
     setTotalSongs(null);
     setPlaytimeCapped(false);
+    setGenres([]);
+    const unknownGenre = t('statistics.decadeUnknown');
     (async () => {
       let playtimeSec = 0;
       let albumsCounted = 0;
       let songsCounted = 0;
+      const genreAgg = new Map<string, { songCount: number; albumCount: number }>();
       let offset = 0;
       const pageSize = 500;
       const maxPages = 10;
@@ -99,7 +98,13 @@ export default function Statistics() {
           for (const a of albums) {
             playtimeSec += a.duration ?? 0;
             albumsCounted += 1;
-            songsCounted += a.songCount ?? 0;
+            const sc = a.songCount ?? 0;
+            songsCounted += sc;
+            const label = (a.genre?.trim()) ? a.genre.trim() : unknownGenre;
+            const cur = genreAgg.get(label) ?? { songCount: 0, albumCount: 0 };
+            cur.songCount += sc;
+            cur.albumCount += 1;
+            genreAgg.set(label, cur);
           }
           if (albums.length < pageSize) break;
           if (page === maxPages - 1) capped = true;
@@ -113,10 +118,14 @@ export default function Statistics() {
         setTotalAlbums(albumsCounted);
         setTotalSongs(songsCounted);
         setPlaytimeCapped(capped);
+        const sorted: SubsonicGenre[] = [...genreAgg.entries()]
+          .map(([value, c]) => ({ value, songCount: c.songCount, albumCount: c.albumCount }))
+          .sort((a, b) => b.songCount - a.songCount);
+        setGenres(sorted);
       }
     })();
     return () => { cancelled = true; };
-  }, [musicLibraryFilterVersion]);
+  }, [musicLibraryFilterVersion, t]);
 
   // Background fetch: format distribution (sample of 500 random songs)
   useEffect(() => {