ui基本完毕，修了一大把的bug

Assets/songsDatabase/dlcData/dlcButton.cs

@@ -42,6 +42,11 @@ public class dlcButton : MonoBehaviour, IPointerEnterHandler, IPointerExitHandle
     private static List<dlcButton> allButtons = new List<dlcButton>();
     private static int selectedIndex = -1;
     private const string PlayerPrefsKey = "dlc_selected_index";
+    private const string SelectedDlcIdPrefsKey = "dlc_selected_id";
+    // When true, Select() applies visual selection but does NOT persist to
+    // PlayerPrefs. Used during restore so re-selecting (including fallback)
+    // never overwrites the user's genuine last choice.
+    public static bool SuppressSelectionPersist = false;
 
     private int instanceIndex = -1;
     private Coroutine hoverCoroutine;
@@ -202,11 +207,38 @@ public class dlcButton : MonoBehaviour, IPointerEnterHandler, IPointerExitHandle
     {
         ApplySelectionToAll(instanceIndex);
         selectedIndex = instanceIndex;
+        if (SuppressSelectionPersist)
+        {
+            if (VerboseLogs) Debug.Log($"dlcButton.Select: '{gameObject.name}' selected (index {instanceIndex}) without persisting (restore in progress)");
+            return;
+        }
         PlayerPrefs.SetInt(PlayerPrefsKey, selectedIndex);
+        int dlcId = ResolveOwnDlcId();
+        if (dlcId > 0)
+        {
+            PlayerPrefs.SetInt(SelectedDlcIdPrefsKey, dlcId);
+        }
         PlayerPrefs.Save();
         if (VerboseLogs) Debug.Log($"dlcButton.Select: '{gameObject.name}' selected (index {instanceIndex}) and saved to PlayerPrefs");
     }
 
+    public static string SelectedDlcIdKey => SelectedDlcIdPrefsKey;
+
+    public int ResolveOwnDlcId()
+    {
+        if (dlcDataSO != null && dlcDataSO.dlcID > 0)
+        {
+            return dlcDataSO.dlcID;
+        }
+
+        if (dlcID != null && int.TryParse(dlcID.text, out int parsedId))
+        {
+            return parsedId;
+        }
+
+        return 0;
+    }
+
     private static void ApplySelectionToAll(int selectIdx)
     {
         for (int i = 0; i < allButtons.Count; i++)