feat(ratings): skip-to-1★ threshold and mix min-rating filter

Add Ratings section under General: manual skip count before setting 1★,
and per-axis minimum stars for random mixes/albums (song, album, artist).
StarRating shows five stars with selection capped at three; shared max in authStore.
Queue filtering via passesMixMinRatings; OpenSubsonic-style entity rating fields on types.

src/utils/mixRatingFilter.ts

@@ -0,0 +1,27 @@
+import type { SubsonicSong } from '../api/subsonic';
+
+export interface MixMinRatingsConfig {
+  enabled: boolean;
+  minSong: number;
+  minAlbum: number;
+  minArtist: number;
+}
+
+/**
+ * Random (and future album) flows: drop songs that are below per-axis thresholds when enabled.
+ * Song axis uses `userRating` (missing = 0). Album/artist use optional OpenSubsonic-style
+ * fields on the song payload; if a threshold is positive but the value is absent, the song is kept.
+ */
+export function passesMixMinRatings(song: SubsonicSong, c: MixMinRatingsConfig): boolean {
+  if (!c.enabled) return true;
+  if (c.minSong > 0 && (song.userRating ?? 0) < c.minSong) return false;
+  if (c.minAlbum > 0) {
+    const r = song.albumUserRating;
+    if (r !== undefined && r < c.minAlbum) return false;
+  }
+  if (c.minArtist > 0) {
+    const r = song.artistUserRating;
+    if (r !== undefined && r < c.minArtist) return false;
+  }
+  return true;
+}