fix: Random Mix improvements, queue UX fixes (v1.4.3)

- Random Mix: remove redundant Play All button in genre mix section
- Random Mix: Play All disabled with live counter during genre mix loading
- Random Mix: cap genre fetch at 50 genres to prevent over-fetching
- Random Mix: cache-bust getRandomSongs to always get fresh results
- Random Mix: clear songs on remix to fix display/play mismatch
- Queue: show song count and total duration in header
- Queue: context-active class keeps hover highlight on right-click
- Context Menu: add Favorite option for queue-item type

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/i18n.ts

@@ -373,7 +373,9 @@ const enTranslation = {
     hide: 'Hide',
     close: 'Close',
     nextTracks: 'Next Tracks',
-    emptyQueue: 'The queue is empty.'
+    emptyQueue: 'The queue is empty.',
+    trackSingular: 'track',
+    trackPlural: 'tracks',
   },
   statistics: {
     title: 'Statistics',
@@ -790,7 +792,9 @@ const deTranslation = {
     hide: 'Verbergen',
     close: 'Schließen',
     nextTracks: 'Nächste Titel',
-    emptyQueue: 'Die Warteschlange ist leer.'
+    emptyQueue: 'Die Warteschlange ist leer.',
+    trackSingular: 'Titel',
+    trackPlural: 'Titel',
   },
   statistics: {
     title: 'Statistiken',