refactor(utils): split componentHelpers grab-bag to owning layers

Per-file routing of the 9-file utils/componentHelpers grab-bag, each driven by
its verified consumer set:
- contextMenu{Actions,Helpers} → features/contextMenu/utils (sole consumer)
- queuePanelHelpers → features/queue/utils (sole consumer)
- nowPlayingHelpers → features/nowPlaying/utils; isRealArtistImage split out to
  cover/ (consumed by cover/artistHero, a lower layer)
- appUpdaterHelpers(+test) + listReorder(+test) → lib/util (config/ + lib/hooks
  consume them; pure)
- playlistDetailHelpers → lib/format (consumed by 3 features; pure)
- appShellHelpers → app/ (app-shell consumers only)
- userMgmtHelpers left in place: consumed by the a11y-HELD SongInfoModal, so a
  move would rewrite a do-not-touch file (same block as licensesData).

Pure moves; tests pass unmodified.

src/features/offline/utils/pinnedOfflineSync.test.ts

@@ -14,7 +14,7 @@ import {
   syncAllPinnedPlaylists,
   syncPinnedArtistIfNeeded,
 } from '@/features/offline/utils/pinnedOfflineSync';
-import { SMART_PREFIX } from '@/utils/componentHelpers/playlistDetailHelpers';
+import { SMART_PREFIX } from '@/lib/format/playlistDetailHelpers';
 
 const getPlaylistMock = vi.fn();
 const getAlbumForServerMock = vi.fn();

src/features/offline/utils/pinnedOfflineSync.ts

@@ -9,7 +9,7 @@ import type { PinSource } from '@/store/localPlaybackStore';
 import { useLocalPlaybackStore } from '@/store/localPlaybackStore';
 import { useOfflineStore } from '@/features/offline/store/offlineStore';
 import { usePlaylistStore } from '@/features/playlist';
-import { isSmartPlaylistName } from '@/utils/componentHelpers/playlistDetailHelpers';
+import { isSmartPlaylistName } from '@/lib/format/playlistDetailHelpers';
 import { getMediaDir } from '@/lib/media/mediaDir';
 import {
   isActiveServerReachable,