feat: Add SoundManager for bg music and opendoor sfx

src/main.js

@@ -2,6 +2,7 @@ import { GameEngine } from './engine/game/GameEngine.js';
 import { GameRenderer } from './view/GameRenderer.js';
 import { CameraManager } from './view/CameraManager.js';
 import { UIManager } from './view/UIManager.js';
+import { SoundManager } from './view/SoundManager.js';
 import { MissionConfig, MISSION_TYPES } from './engine/dungeon/MissionConfig.js';
 
 
@@ -19,10 +20,15 @@ const renderer = new GameRenderer('app');
 const cameraManager = new CameraManager(renderer);
 const game = new GameEngine();
 const ui = new UIManager(cameraManager, game);
+const soundManager = new SoundManager();
+
+// Start Music (Autoplay handling included in manager)
+soundManager.playMusic('exploration');
 
 // Global Access
 window.GAME = game;
 window.RENDERER = renderer;
+window.SOUND_MANAGER = soundManager;
 
 // 3. Connect Dungeon Generator to Renderer
 const generator = game.dungeon;
@@ -222,6 +228,7 @@ const handleClick = (x, y, doorMesh) => {
 
                 // Open door visually
                 renderer.openDoor(doorMesh);
+                if (window.SOUND_MANAGER) window.SOUND_MANAGER.playSound('door_open');
 
                 // Get proper exit data with direction
                 const exitData = doorMesh.userData.exitData;