存档重构，游戏内容解锁机制；教程完善（未完成）

Assets/Scripts/UI/SongSelection/SongSelectionTab.cs

@@ -16,6 +16,10 @@ namespace Ichni.Menu
     {
         private SongListControllerUI songListController => MenuManager.instance.songSelectionUIPage.songListController;
 
+        /// <summary>
+        /// 供锁标识和预览滤镜使用的运行时状态。进入歌曲前必须调用 <see cref="RefreshUnlockState"/>
+        /// 重新计算，不能把缓存的显示状态当作最终授权结果。
+        /// </summary>
         public bool isLocked;
         
         public SongItemData connectedSong;
@@ -38,13 +42,26 @@ namespace Ichni.Menu
             songNameText.text = song.displaySongName;
             composerNameText.text = song.composer;
 
-            isLocked = !GameSaveManager.instance.SongSaveModule.CheckStoryKey(song.storyUnlockKey);
-            lockMark.gameObject.SetActive(isLocked);
+            RefreshUnlockState();
             
             quickSwitchButton.onClick.AddListener(() =>
             {
                 if (MenuManager.instance.songSelectionUIPage.songListController.selectedTab == this)
                 {
+                    SongSelectionUIPage songSelectionUIPage = MenuManager.instance.songSelectionUIPage;
+
+                    // 快速进入会绕过 PlaySongUI 的 Button.interactable，必须在此处重复保护空难度状态。
+                    if (songSelectionUIPage.selectedSong == null || songSelectionUIPage.selectedDifficulty == null)
+                    {
+                        return;
+                    }
+
+                    // 快速进入与标准 Play 共用统一的章节 + 歌曲授权检查，不能因 UI 状态过期而绕过锁定。
+                    if (!RefreshUnlockState())
+                    {
+                        return;
+                    }
+
                     if (MenuManager.instance.isEnteringGame)
                     {
                         return;
@@ -53,9 +70,9 @@ namespace Ichni.Menu
                     MenuManager.instance.isEnteringGame = true;
                     
                     InformationTransistor.instance.SetInformation(
-                        ChapterSelectionManager.instance.currentChapter, 
-                        MenuManager.instance.songSelectionUIPage.selectedSong, 
-                        MenuManager.instance.songSelectionUIPage.selectedDifficulty);
+                        ChapterSelectionManager.instance.currentChapter,
+                        songSelectionUIPage.selectedSong,
+                        songSelectionUIPage.selectedDifficulty);
                     
                     AudioManager.Post(AK.EVENTS.ENTERTOGAME);
                     SongSelectionManager.instance.StopPreviewSong();
@@ -74,6 +91,25 @@ namespace Ichni.Menu
             });
         }
 
+        /// <summary>
+        /// 重新计算当前 Tab 是否锁定，并同步锁图标。
+        /// 章节本身被锁定时，即使歌曲规则无条件开放，也仍然视为不可进入。
+        /// </summary>
+        /// <returns>返回 true 表示当前章节和歌曲均允许进入。</returns>
+        public bool RefreshUnlockState()
+        {
+            UnlockSaveModule unlockSaveModule = GameSaveManager.instance?.UnlockSaveModule;
+            ChapterSelectionUnit currentChapter = ChapterSelectionManager.instance?.currentChapter;
+            isLocked = unlockSaveModule == null || !unlockSaveModule.CanEnterSong(currentChapter, connectedSong);
+
+            if (lockMark != null)
+            {
+                lockMark.gameObject.SetActive(isLocked);
+            }
+
+            return !isLocked;
+        }
+
         private void Update()
         {
             RectTransform centerPoint = songListController.centerPoint;
@@ -113,4 +149,4 @@ namespace Ichni.Menu
             }
         }
     }
-}
+}