fix: bind captionsEnabled between App and VideoPlayer for Player mode CC sync

Co-authored-by: Cursor <cursoragent@cursor.com>

src/App.svelte

@@ -406,7 +406,7 @@
 
     <!-- Video area: always mounted, never destroyed -->
     <div class="video-area" class:player-video={isPlayerMode}>
-      <VideoPlayer />
+      <VideoPlayer bind:captionsEnabled />
       {#if isPlayerMode}
         <PlayerControls
           visible={showPlayerControls}