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/playlist/PlaylistSongSearchPanel.tsx

@@ -5,7 +5,7 @@ import { buildCoverArtUrl, coverArtCacheKey } from '../../api/subsonicStreamUrl'
 import type { SubsonicSong } from '../../api/subsonicTypes';
 import { usePlayerStore } from '../../store/playerStore';
 import { songToTrack } from '../../utils/playback/songToTrack';
-import { formatDuration } from '../../utils/componentHelpers/playlistDetailHelpers';
+import { formatTrackTime } from '../../utils/format/formatDuration';
 import CachedImage from '../CachedImage';
 import { AddToPlaylistSubmenu } from '../ContextMenu';
 
@@ -132,7 +132,7 @@ export default function PlaylistSongSearchPanel({
               <span className="playlist-search-title">{song.title}</span>
               <span className="playlist-search-artist">{song.artist} · <span className="playlist-search-album">{song.album}</span></span>
             </div>
-            <span className="playlist-search-duration">{formatDuration(song.duration ?? 0)}</span>
+            <span className="playlist-search-duration">{formatTrackTime(song.duration ?? 0)}</span>
           </div>
         );
       })}

src/components/playlist/PlaylistSuggestions.tsx

@@ -8,7 +8,8 @@ import { usePlayerStore } from '../../store/playerStore';
 import { usePreviewStore } from '../../store/previewStore';
 import { useThemeStore } from '../../store/themeStore';
 import { songToTrack } from '../../utils/playback/songToTrack';
-import { codecLabel, formatDuration } from '../../utils/componentHelpers/playlistDetailHelpers';
+import { codecLabel } from '../../utils/componentHelpers/playlistDetailHelpers';
+import { formatTrackTime } from '../../utils/format/formatDuration';
 
 const PL_CENTERED = new Set(['favorite', 'rating', 'duration']);
 
@@ -156,7 +157,7 @@ export default function PlaylistSuggestions({
                   );
                   case 'favorite': return <div key="favorite" />;
                   case 'rating': return <div key="rating" />;
-                  case 'duration': return <div key="duration" className="track-duration">{formatDuration(song.duration ?? 0)}</div>;
+                  case 'duration': return <div key="duration" className="track-duration">{formatTrackTime(song.duration ?? 0)}</div>;
                   case 'format': return (
                     <div key="format" className="track-meta">
                       {(song.suffix || (showBitrate && song.bitRate)) && <span className="track-codec">{codecLabel(song, showBitrate)}</span>}

src/components/playlist/PlaylistTracklist.tsx

@@ -13,7 +13,8 @@ import { useThemeStore } from '../../store/themeStore';
 import { useDragDrop } from '../../contexts/DragDropContext';
 import { useOrbitSongRowBehavior } from '../../hooks/useOrbitSongRowBehavior';
 import { songToTrack } from '../../utils/playback/songToTrack';
-import { codecLabel, formatDuration } from '../../utils/componentHelpers/playlistDetailHelpers';
+import { codecLabel } from '../../utils/componentHelpers/playlistDetailHelpers';
+import { formatTrackTime } from '../../utils/format/formatDuration';
 import type { PlaylistSortKey, PlaylistSortDir } from '../../utils/playlist/playlistDisplayedSongs';
 import StarRating from '../StarRating';
 import { AddToPlaylistSubmenu } from '../ContextMenu';
@@ -405,7 +406,7 @@ export default function PlaylistTracklist({
                   </div>
                 );
                 case 'rating': return <StarRating key="rating" value={ratings[song.id] ?? userRatingOverrides[song.id] ?? song.userRating ?? 0} onChange={r => handleRate(song.id, r)} />;
-                case 'duration': return <div key="duration" className="track-duration">{formatDuration(song.duration ?? 0)}</div>;
+                case 'duration': return <div key="duration" className="track-duration">{formatTrackTime(song.duration ?? 0)}</div>;
                 case 'format': return (
                   <div key="format" className="track-meta">
                     {(song.suffix || (showBitrate && song.bitRate)) && <span className="track-codec">{codecLabel(song, showBitrate)}</span>}