refactor(context-menu): H.1–H.12 — extract submenus + 5 type-branch components + hooks (Phase H start) (#662)

* refactor(context-menu): H.1 — extract helpers + constants

* refactor(context-menu): H.2 — extract AddToPlaylistSubmenu component

* refactor(context-menu): H.3 — extract AlbumToPlaylistSubmenu + ArtistToPlaylistSubmenu

* refactor(context-menu): H.4 — extract MultiAlbumToPlaylistSubmenu

* refactor(context-menu): H.5 — extract MultiArtistToPlaylistSubmenu

* refactor(context-menu): H.6 — extract SinglePlaylist + MultiPlaylist submenus

* refactor(context-menu): H.7 — extract startRadio/startInstantMix/downloadAlbum/copyShareLink actions

* refactor(context-menu): H.8 — extract useContextMenuKeyboardNav hook

* refactor(context-menu): H.9 — extract useContextMenuRating hook

* refactor(context-menu): H.10 — extract ContextMenuItems (all 9 type branches)

* refactor(context-menu): H.11 — split ContextMenuItems into 5 type-branch files

ContextMenuItems.tsx (800 LOC) was just a moved 400-LOC-cap violation.
Now ContextMenuItems is a 30-LOC switch that dispatches to:
  - SongContextItems       (song + album-song + favorite-song)
  - QueueItemContextItems  (queue-item)
  - AlbumContextItems      (album + multi-album)
  - ArtistContextItems     (artist + multi-artist)
  - PlaylistContextItems   (playlist + multi-playlist)

All five branch files are now under 330 LOC; ContextMenu.tsx itself stays
at 194 LOC. Shared Props interface lives in contextMenuItemTypes.ts.

* refactor(context-menu): H.12 — strip unused imports from branch components

src/hooks/useContextMenuRating.ts

@@ -0,0 +1,127 @@
+import { useCallback } from 'react';
+import { setRating } from '../api/subsonicStarRating';
+import type { SubsonicAlbum, SubsonicArtist } from '../api/subsonicTypes';
+import type { Track } from '../store/playerStoreTypes';
+import { useAuthStore } from '../store/authStore';
+import { showToast } from '../utils/toast';
+
+type RatingKind = 'song' | 'album' | 'artist';
+
+interface Args {
+  type: string | null;
+  item: unknown;
+  userRatingOverrides: Record<string, number>;
+  setUserRatingOverride: (id: string, rating: number) => void;
+  entityRatingSupport: 'full' | 'track_only' | 'unknown';
+  t: (key: string) => string;
+}
+
+interface Result {
+  applySongRating: (songId: string, rating: number) => void;
+  applyAlbumRating: (album: SubsonicAlbum, rating: number) => void;
+  applyArtistRating: (artist: SubsonicArtist, rating: number) => void;
+  getRatingValueByKind: (kind: RatingKind, id: string) => number;
+  commitRatingByKind: (kind: RatingKind, id: string, rating: number) => void;
+}
+
+export function useContextMenuRating({
+  type, item, userRatingOverrides, setUserRatingOverride, entityRatingSupport, t,
+}: Args): Result {
+  const setEntityRatingSupport = useAuthStore(s => s.setEntityRatingSupport);
+  const activeServerId = useAuthStore(s => s.activeServerId);
+
+  const applySongRating = useCallback((songId: string, rating: number) => {
+    setUserRatingOverride(songId, rating);
+    setRating(songId, rating).catch(() => {});
+  }, [setUserRatingOverride]);
+
+  const applyAlbumRating = useCallback((album: SubsonicAlbum, rating: number) => {
+    setUserRatingOverride(album.id, rating);
+    if (entityRatingSupport !== 'full') return;
+    setRating(album.id, rating).catch(err => {
+      if (activeServerId) setEntityRatingSupport(activeServerId, 'track_only');
+      showToast(
+        typeof err === 'string' ? err : err instanceof Error ? err.message : t('entityRating.saveFailed'),
+        4500,
+        'error',
+      );
+    });
+  }, [setUserRatingOverride, entityRatingSupport, activeServerId, setEntityRatingSupport, t]);
+
+  const applyArtistRating = useCallback((artist: SubsonicArtist, rating: number) => {
+    setUserRatingOverride(artist.id, rating);
+    if (entityRatingSupport !== 'full') return;
+    setRating(artist.id, rating).catch(err => {
+      if (activeServerId) setEntityRatingSupport(activeServerId, 'track_only');
+      showToast(
+        typeof err === 'string' ? err : err instanceof Error ? err.message : t('entityRating.saveFailed'),
+        4500,
+        'error',
+      );
+    });
+  }, [setUserRatingOverride, entityRatingSupport, activeServerId, setEntityRatingSupport, t]);
+
+  const getRatingValueByKind = useCallback((kind: RatingKind, id: string): number => {
+    if (kind === 'song' && (type === 'song' || type === 'album-song' || type === 'queue-item')) {
+      const song = item as Track;
+      if (song.id === id) return userRatingOverrides[id] ?? song.userRating ?? 0;
+    }
+    if (kind === 'album' && type === 'album') {
+      const album = item as SubsonicAlbum;
+      if (album.id === id) return userRatingOverrides[id] ?? album.userRating ?? 0;
+    }
+    if (kind === 'album' && type === 'multi-album') {
+      const albums = item as SubsonicAlbum[];
+      const compositeId = [...albums.map(a => a.id)].sort().join('\x1e');
+      if (id !== compositeId) return userRatingOverrides[id] ?? 0;
+      if (albums.length === 0) return 0;
+      const vals = albums.map(a => userRatingOverrides[a.id] ?? a.userRating ?? 0);
+      const first = vals[0];
+      return vals.every(v => v === first) ? first : 0;
+    }
+    if (kind === 'artist' && type === 'artist') {
+      const artist = item as SubsonicArtist;
+      if (artist.id === id) return userRatingOverrides[id] ?? artist.userRating ?? 0;
+    }
+    if (kind === 'artist' && type === 'multi-artist') {
+      const artists = item as SubsonicArtist[];
+      const compositeId = [...artists.map(a => a.id)].sort().join('\x1e');
+      if (id !== compositeId) return userRatingOverrides[id] ?? 0;
+      if (artists.length === 0) return 0;
+      const vals = artists.map(a => userRatingOverrides[a.id] ?? a.userRating ?? 0);
+      const first = vals[0];
+      return vals.every(v => v === first) ? first : 0;
+    }
+    return userRatingOverrides[id] ?? 0;
+  }, [type, item, userRatingOverrides]);
+
+  const commitRatingByKind = useCallback((kind: RatingKind, id: string, rating: number) => {
+    if (kind === 'song') {
+      applySongRating(id, rating);
+      return;
+    }
+    if (kind === 'album' && type === 'album') {
+      applyAlbumRating(item as SubsonicAlbum, rating);
+      return;
+    }
+    if (kind === 'album' && type === 'multi-album') {
+      const albums = item as SubsonicAlbum[];
+      const compositeId = [...albums.map(a => a.id)].sort().join('\x1e');
+      if (id !== compositeId) return;
+      for (const a of albums) applyAlbumRating(a, rating);
+      return;
+    }
+    if (kind === 'artist' && type === 'artist') {
+      applyArtistRating(item as SubsonicArtist, rating);
+      return;
+    }
+    if (kind === 'artist' && type === 'multi-artist') {
+      const artists = item as SubsonicArtist[];
+      const compositeId = [...artists.map(a => a.id)].sort().join('\x1e');
+      if (id !== compositeId) return;
+      for (const a of artists) applyArtistRating(a, rating);
+    }
+  }, [applySongRating, applyAlbumRating, applyArtistRating, type, item]);
+
+  return { applySongRating, applyAlbumRating, applyArtistRating, getRatingValueByKind, commitRatingByKind };
+}