feat: BGMController独立音频脚本—彻底脱离PageController复杂编辑历史

新增BGMController.cs挂在[Managers]上:
- Awake()中创建AudioSource(spatialBlend=0,vol=0.5)
- AssetDatabase兜底加载_homeBgClip/_experimentBgClip
- 静态方法PlayHomeBg/PlayExperimentBg/StopBgMusic
PageController调用改为BGMController.xxx

Assets/Scripts/Audio/BGMController.cs

@@ -0,0 +1,54 @@
+using UnityEngine;
+
+/// <summary>
+/// 背景音乐控制器——挂在 [Managers] 上，独立于 PageController。
+/// 静态方法供外部调用。
+/// </summary>
+public class BGMController : MonoBehaviour
+{
+    [SerializeField] private AudioClip _homeBgClip;
+    [SerializeField] private AudioClip _experimentBgClip;
+    private AudioSource _bgSource;
+
+    private static BGMController _instance;
+
+    void Awake()
+    {
+        _instance = this;
+        _bgSource = gameObject.AddComponent<AudioSource>();
+        _bgSource.loop = true;
+        _bgSource.playOnAwake = false;
+        _bgSource.spatialBlend = 0f;
+        _bgSource.volume = 0.5f;
+
+#if UNITY_EDITOR
+        if (_homeBgClip == null) _homeBgClip = UnityEditor.AssetDatabase.LoadAssetAtPath<AudioClip>("Assets/Audio/homeBackgroundMusic.mp3");
+        if (_experimentBgClip == null) _experimentBgClip = UnityEditor.AssetDatabase.LoadAssetAtPath<AudioClip>("Assets/Audio/backgroundMusic.mp3");
+#endif
+        Debug.Log($"[BGMController] 就绪 homeBg={(_homeBgClip!=null)} expBg={(_experimentBgClip!=null)}");
+    }
+
+    public static void PlayHomeBg()
+    {
+        if (_instance == null || _instance._homeBgClip == null) { Debug.LogWarning("[BGMController] PlayHomeBg 失败"); return; }
+        _instance._bgSource.clip = _instance._homeBgClip;
+        _instance._bgSource.volume = 0.5f;
+        _instance._bgSource.Play();
+        Debug.Log($"[BGMController] 播放首页bg isPlaying={_instance._bgSource.isPlaying}");
+    }
+
+    public static void PlayExperimentBg()
+    {
+        if (_instance == null || _instance._experimentBgClip == null) { Debug.LogWarning("[BGMController] PlayExperimentBg 失败"); return; }
+        _instance._bgSource.clip = _instance._experimentBgClip;
+        _instance._bgSource.volume = 0.5f;
+        _instance._bgSource.Play();
+        Debug.Log($"[BGMController] 播放实验bg isPlaying={_instance._bgSource.isPlaying}");
+    }
+
+    public static void StopBgMusic()
+    {
+        if (_instance != null) _instance._bgSource.Stop();
+        Debug.Log("[BGMController] 停止bg");
+    }
+}

Assets/Scripts/Audio/BGMController.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: d5a0e43c7217447f9b4be5e2434520e4
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Scripts/UI/PageController.cs

@@ -128,8 +128,8 @@ public class PageController : MonoBehaviour
 
         if (_uiManager != null)
             _uiManager.enabled = (page == Page.Experiment);
-        if (page == Page.Home) PlayHomeBg();        // 背景音乐: 首页播 homeBg, 选固定方式时停, 实验启动时播 experimentBg
-        if (page == Page.Home) PlayHomeBg();
+        if (page == Page.Home) BGMController.PlayHomeBg();        // 背景音乐: 首页播 homeBg, 选固定方式时停, 实验启动时播 experimentBg
+        if (page == Page.Home) BGMController.PlayHomeBg();
         Debug.Log($"PageController（编辑器预览）: 切换到 [{page}]");
     }
 #endif
@@ -231,7 +231,7 @@ public class PageController : MonoBehaviour
         Debug.Log($"PageController: GameManager 已设置 Mode=[{gm.CurrentMode}] Fixation=[{gm.CurrentFixationMethod}]");
 
         // 隐藏所有UI面板，准备播放片头动画
-        StopBgMusic();
+        BGMController.StopBgMusic();
         HideAllPages();
 
         // 找到 OpeningFlowController 播放片头动画