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/queue/components/QueueCurrentTrack.tsx

@@ -7,7 +7,7 @@ import type { PlaybackSourceKind } from '@/features/playback/utils/playback/reso
 import {
   formatQueueReplayGainParts,
   renderStars,
-} from '@/utils/componentHelpers/queuePanelHelpers';
+} from '@/features/queue/utils/queuePanelHelpers';
 import { loudnessGainPlaceholderUntilCacheDb } from '@/features/playback/utils/audio/loudnessPlaceholder';
 import { effectiveLoudnessPreAnalysisAttenuationDb } from '@/lib/audio/loudnessPreAnalysisSlider';
 import { formatQueueBpmTech, formatQueueMoodLabels } from '@/lib/library/trackEnrichment';

src/features/queue/components/QueueHeader.tsx

@@ -6,7 +6,7 @@ import { usePlayerStore } from '@/features/playback/store/playerStore';
 import { useAuthStore } from '@/store/authStore';
 import type { QueueItemRef } from '@/lib/media/trackTypes';
 import type { QueueDisplayMode } from '@/store/authStoreTypes';
-import type { DurationMode } from '@/utils/componentHelpers/queuePanelHelpers';
+import type { DurationMode } from '@/features/queue/utils/queuePanelHelpers';
 import { formatLongDuration } from '@/lib/format/formatDuration';
 import { formatClockTime } from '@/lib/format/formatClockTime';
 import { resolveQueueTrack } from '@/features/playback/store/queueTrackView';