feat(mini-player): user-bindable keyboard shortcut to toggle mini player

Adds an 'open-mini-player' entry to the in-app keybindings (Settings →
Shortcuts), default unbound. Pressing the chord from the main window
opens the mini and minimises main; pressing it from the mini hides the
mini and restores main — both paths invoke open_mini_player which
already handles the toggle.

The mini window has its own keydown listener (same pattern as Space /
arrows for play/skip) that reads the binding from useKeybindingsStore.
Binding changes in main propagate to an open mini through the existing
storage-event sync (now also covers psysonic_keybindings) so the user
doesn't need to restart the mini after rebinding.

Localized in all 8 supported locales.

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

src/locales/de.ts

@@ -642,6 +642,7 @@ export const deTranslation = {
     shortcutOpenFolderBrowser: '{{folderBrowser}} öffnen',
     shortcutFullscreenPlayer: 'Vollbild-Player',
     shortcutNativeFullscreen: 'Nativer Vollbildmodus',
+    shortcutOpenMiniPlayer: 'Mini-Player öffnen',
     tabSystem: 'System',
     tabGeneral: 'Allgemein',
     ratingsSectionTitle: 'Bewertungen',

src/locales/en.ts

@@ -667,6 +667,7 @@ export const enTranslation = {
     shortcutOpenFolderBrowser: 'Open {{folderBrowser}}',
     shortcutFullscreenPlayer: 'Fullscreen player',
     shortcutNativeFullscreen: 'Native fullscreen',
+    shortcutOpenMiniPlayer: 'Open mini player',
     playbackTitle: 'Playback',
     replayGain: 'Replay Gain',
     replayGainDesc: 'Normalize track volume using ReplayGain metadata',

src/locales/es.ts

@@ -658,6 +658,7 @@ export const esTranslation = {
     shortcutOpenFolderBrowser: 'Abrir {{folderBrowser}}',
     shortcutFullscreenPlayer: 'Reproductor pantalla completa',
     shortcutNativeFullscreen: 'Pantalla completa nativa',
+    shortcutOpenMiniPlayer: 'Abrir mini reproductor',
     playbackTitle: 'Reproducción',
     replayGain: 'Replay Gain',
     replayGainDesc: 'Normalizar volumen de pistas usando metadatos ReplayGain',

src/locales/fr.ts

@@ -630,6 +630,7 @@ export const frTranslation = {
     shortcutOpenFolderBrowser: 'Ouvrir {{folderBrowser}}',
     shortcutFullscreenPlayer: 'Lecteur plein écran',
     shortcutNativeFullscreen: 'Plein écran natif',
+    shortcutOpenMiniPlayer: 'Ouvrir le mini-lecteur',
     tabSystem: 'Système',
     tabGeneral: 'Général',
     ratingsSectionTitle: 'Notes',

src/locales/nb.ts

@@ -652,6 +652,7 @@ export const nbTranslation = {
     shortcutOpenFolderBrowser: 'Åpne {{folderBrowser}}',
     shortcutFullscreenPlayer: 'Fullskjermsspiller',
     shortcutNativeFullscreen: 'Naturlig fullskjerm',
+    shortcutOpenMiniPlayer: 'Åpne minispiller',
     playbackTitle: 'Avspilling',
     replayGain: 'Replay Gain',
     replayGainDesc: 'Normaliser sporvolumet ved hjelp av ReplayGain-metadata',

src/locales/nl.ts

@@ -629,6 +629,7 @@ export const nlTranslation = {
     shortcutOpenFolderBrowser: '{{folderBrowser}} openen',
     shortcutFullscreenPlayer: 'Volledigschermspeler',
     shortcutNativeFullscreen: 'Systeemvolledig scherm',
+    shortcutOpenMiniPlayer: 'Mini-speler openen',
     tabSystem: 'Systeem',
     tabGeneral: 'Algemeen',
     ratingsSectionTitle: 'Beoordelingen',

src/locales/ru.ts

@@ -682,6 +682,7 @@ export const ruTranslation = {
     shortcutOpenFolderBrowser: 'Открыть {{folderBrowser}}',
     shortcutFullscreenPlayer: 'Полноэкранный плеер',
     shortcutNativeFullscreen: 'Системный полный экран',
+    shortcutOpenMiniPlayer: 'Открыть мини-плеер',
     playbackTitle: 'Воспроизведение',
     replayGain: 'Replay Gain',
     replayGainDesc: 'Выравнивание громкости по метаданным ReplayGain',

src/locales/zh.ts

@@ -648,6 +648,7 @@ export const zhTranslation = {
     shortcutOpenFolderBrowser: '打开{{folderBrowser}}',
     shortcutFullscreenPlayer: '全屏播放器',
     shortcutNativeFullscreen: '原生全屏',
+    shortcutOpenMiniPlayer: '打开迷你播放器',
     playbackTitle: '播放',
     replayGain: '回放增益',
     replayGainDesc: '使用 ReplayGain 元数据标准化曲目音量',