refactor(format): consolidate duration formatters into format/formatDuration (Phase L, part 2) (#690)

The mm:ss track-time formatter was hand-rolled in 11 places and the
h:mm:ss total-duration formatter in 4 — extract two tested functions:

- formatTrackTime(seconds, fallback='0:00')  — m:ss, used for track /
  playback times. fallback param covers the '–' placeholder rows.
- formatLongDuration(seconds)                — h:mm:ss when >=1h, else
  m:ss, used for album / queue totals.

Behaviour preserved per call site: the unified guard
(!seconds || !isFinite || <0 -> fallback) produces identical output to
every prior variant for all real inputs; SongRow keeps its '–' via the
fallback arg. Removes the formatter exports from 6 componentHelpers
files (playerBarHelpers / fullscreenPlayerHelpers deleted — they only
exported the formatter) and 7 inline component copies.

+ formatDuration.test.ts

src/components/artistDetail/ArtistDetailTopTracks.tsx

@@ -6,7 +6,7 @@ import { usePlayerStore } from '../../store/playerStore';
 import { usePreviewStore } from '../../store/previewStore';
 import { useOrbitSongRowBehavior } from '../../hooks/useOrbitSongRowBehavior';
 import { songToTrack } from '../../utils/playback/songToTrack';
-import { formatDuration } from '../../utils/componentHelpers/artistDetailHelpers';
+import { formatTrackTime } from '../../utils/format/formatDuration';
 import ArtistSuggestionTrackCover from './ArtistSuggestionTrackCover';
 
 interface Props {
@@ -100,7 +100,7 @@ export default function ArtistDetailTopTracks({ topSongs, marginTop, playTopSong
           {song.album}
         </div>
         <div className="track-duration" style={{ textAlign: 'right' }}>
-        {formatDuration(song.duration)}
+        {formatTrackTime(song.duration)}
          </div>
        </div>
        );