Add music and voice assets

src/game/scenes/StoryScene.ts

@@ -1,4 +1,5 @@
 import Phaser from 'phaser';
+import { soundDirector } from '../audio/SoundDirector';
 import { prologuePages, type PortraitKey, type StoryPage } from '../data/scenario';
 import { palette } from '../ui/palette';
 
@@ -114,6 +115,8 @@ export class StoryScene extends Phaser.Scene {
   }
 
   private applyPage(page: StoryPage) {
+    soundDirector.playMusic(page.bgm);
+    soundDirector.playVoice(page.voice, page.voiceRole ?? page.portrait ?? 'narrator');
     this.applyBackground(page.background);
     this.chapterText?.setText(page.chapter);