feat(mini-player): custom titlebar with action icons; cover/meta/controls layout polish

- Drop the native titlebar on Windows + Linux (decorations: false in
  open_mini_player); macOS keeps the system titlebar with traffic lights.
- Add a slim 26 px custom titlebar with drag region, current track
  title, and the queue / pin / open-main / close action icons.
- Remove the bottom toolbar — those four buttons now live in the
  titlebar where they're easier to reach.
- Refresh the player layout: cover shrinks 112 → 84 px, the right
  column gets title / artist / transport in a single 84 px-tall block,
  progress bar spans the full width below.
- Add a miniPlayer i18n namespace (showQueue, hideQueue, pinOnTop,
  pinOff, openMainWindow, close, emptyQueue) localized for all 8
  supported locales — previously the tooltips were hard-coded English.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/locales/de.ts

@@ -913,6 +913,15 @@ export const deTranslation = {
     sourceHot: 'Wiedergabe aus dem Cache',
     sourceStream: 'Wiedergabe aus dem Netzwerkstream',
   },
+  miniPlayer: {
+    showQueue: 'Warteschlange einblenden',
+    hideQueue: 'Warteschlange ausblenden',
+    pinOnTop: 'Im Vordergrund halten',
+    pinOff: 'Vordergrund deaktivieren',
+    openMainWindow: 'Hauptfenster öffnen',
+    close: 'Schließen',
+    emptyQueue: 'Die Warteschlange ist leer',
+  },
   statistics: {
     title: 'Statistiken',
     recentlyPlayed: 'Zuletzt gehört',

src/locales/en.ts

@@ -915,6 +915,15 @@ export const enTranslation = {
     sourceHot: 'Playing from cache',
     sourceStream: 'Playing from network stream',
   },
+  miniPlayer: {
+    showQueue: 'Show queue',
+    hideQueue: 'Hide queue',
+    pinOnTop: 'Pin on top',
+    pinOff: 'Unpin',
+    openMainWindow: 'Open main window',
+    close: 'Close',
+    emptyQueue: 'Queue is empty',
+  },
   statistics: {
     title: 'Statistics',
     recentlyPlayed: 'Recently Played',

src/locales/es.ts

@@ -906,6 +906,15 @@ export const esTranslation = {
     sourceHot: 'Reproducción desde la caché',
     sourceStream: 'Reproducción desde la transmisión en red',
   },
+  miniPlayer: {
+    showQueue: 'Mostrar cola',
+    hideQueue: 'Ocultar cola',
+    pinOnTop: 'Mantener encima',
+    pinOff: 'Desfijar',
+    openMainWindow: 'Abrir ventana principal',
+    close: 'Cerrar',
+    emptyQueue: 'La cola está vacía',
+  },
   statistics: {
     title: 'Estadísticas',
     recentlyPlayed: 'Reproducidos Recientemente',

src/locales/fr.ts

@@ -901,6 +901,15 @@ export const frTranslation = {
     sourceHot: 'Lecture depuis le cache',
     sourceStream: 'Lecture depuis le flux réseau',
   },
+  miniPlayer: {
+    showQueue: 'Afficher la file',
+    hideQueue: 'Masquer la file',
+    pinOnTop: 'Toujours visible',
+    pinOff: 'Désépingler',
+    openMainWindow: 'Ouvrir la fenêtre principale',
+    close: 'Fermer',
+    emptyQueue: 'La file est vide',
+  },
   statistics: {
     title: 'Statistiques',
     recentlyPlayed: 'Écoutés récemment',

src/locales/nb.ts

@@ -900,6 +900,15 @@ export const nbTranslation = {
     sourceHot: 'Spiller fra cache',
     sourceStream: 'Spiller fra nettverksstrøm',
   },
+  miniPlayer: {
+    showQueue: 'Vis kø',
+    hideQueue: 'Skjul kø',
+    pinOnTop: 'Hold øverst',
+    pinOff: 'Løsne',
+    openMainWindow: 'Åpne hovedvindu',
+    close: 'Lukk',
+    emptyQueue: 'Køen er tom',
+  },
   statistics: {
     title: 'Statistikk',
     recentlyPlayed: 'Nylig spilt',

src/locales/nl.ts

@@ -900,6 +900,15 @@ export const nlTranslation = {
     sourceHot: 'Afspelen vanuit cache',
     sourceStream: 'Afspelen vanuit netwerkstream',
   },
+  miniPlayer: {
+    showQueue: 'Wachtrij tonen',
+    hideQueue: 'Wachtrij verbergen',
+    pinOnTop: 'Altijd boven',
+    pinOff: 'Losmaken',
+    openMainWindow: 'Hoofdvenster openen',
+    close: 'Sluiten',
+    emptyQueue: 'Wachtrij is leeg',
+  },
   statistics: {
     title: 'Statistieken',
     recentlyPlayed: 'Recent afgespeeld',

src/locales/ru.ts

@@ -953,6 +953,15 @@ export const ruTranslation = {
     sourceHot: 'Играет из кэша',
     sourceStream: 'Играет из сетевого потока',
   },
+  miniPlayer: {
+    showQueue: 'Показать очередь',
+    hideQueue: 'Скрыть очередь',
+    pinOnTop: 'Поверх окон',
+    pinOff: 'Открепить',
+    openMainWindow: 'Открыть главное окно',
+    close: 'Закрыть',
+    emptyQueue: 'Очередь пуста',
+  },
   statistics: {
     title: 'Статистика',
     recentlyPlayed: 'Недавно проиграно',

src/locales/zh.ts

@@ -896,6 +896,15 @@ export const zhTranslation = {
     sourceHot: '正在从缓存播放',
     sourceStream: '正在从网络流播放',
   },
+  miniPlayer: {
+    showQueue: '显示队列',
+    hideQueue: '隐藏队列',
+    pinOnTop: '置顶',
+    pinOff: '取消置顶',
+    openMainWindow: '打开主窗口',
+    close: '关闭',
+    emptyQueue: '队列为空',
+  },
   statistics: {
     title: '统计',
     recentlyPlayed: '最近播放',