feat: track info drawer (Get Info-style)

Add a right-side track info drawer that sits to the right of the queue
panel when both are open. Shows a large cover, title/artist/album links,
a Play/Queue/Edit actions row, and Status/General/File/Identifiers
sections (empty rows omitted). Opens from the track context menu, the
player now-playing tile, and the queue now-playing card.

- ui slice: trackInfoId + open/closeTrackInfo
- TrackInfoDrawer rendered after QueuePanel in AppShell; overlays content
  on narrow viewports
- map source/createdAt/enrichedAt from the wire (were unmapped)
- formatDateTime helper, info icon, i18n (en/ru)
- drop orphaned toggleNowPlaying/isNowPlayingOpen from player slice

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/lib/format.ts

@@ -16,6 +16,16 @@ export function formatFileSize(bytes: number): string {
   return `${(bytes / (1024 * 1024 * 1024)).toFixed(2)} GB`;
 }
 
+export function formatDateTime(iso: string | undefined): string | undefined {
+  if (!iso) return undefined;
+  const d = new Date(iso);
+  if (Number.isNaN(d.getTime())) return undefined;
+  return new Intl.DateTimeFormat(undefined, {
+    dateStyle: 'medium',
+    timeStyle: 'short',
+  }).format(d);
+}
+
 export function formatCount(n: number): string {
   if (n < 1000) return String(n);
   if (n < 1_000_000) return `${(n / 1000).toFixed(1)}K`;