feat(player): queue undo/redo with hotkeys and playback-aware restore

Snapshot queue, current track, time, and pause before queue mutations.
Ctrl+Z/Cmd+Z restores prior state; Ctrl+Shift+Z/Cmd+Shift+Z reapplies undone
edits when the redo stack is non-empty; new edits clear redo.

Resync the Rust audio engine only when the current song identity changes
from the pre-apply state so reorder/enqueue-style edits keep live playback.

Register the document capture listener from main.tsx after the window label
is set. Mini player forwards undo/redo via mini:undo-queue and mini:redo-queue.

src/main.tsx

@@ -3,6 +3,7 @@ import ReactDOM from 'react-dom/client';
 import { invoke } from '@tauri-apps/api/core';
 import { getCurrentWindow } from '@tauri-apps/api/window';
 import App from './App';
+import { installQueueUndoHotkey } from './store/playerStore';
 import './i18n';
 import './styles/theme.css';
 import './styles/layout.css';
@@ -46,6 +47,8 @@ try {
   // Ignore parse / non-Tauri.
 }
 
+installQueueUndoHotkey();
+
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <StrictMode>
     <App />