fix: stabilize ping undo state and prevent negative ping steps

Assets/Scripts/Core/StepManager.cs

@@ -221,7 +221,7 @@ public class StepManager : MonoBehaviour
 
     public void DecrementPingStep()
     {
-        _pingStepIndex--;
+        _pingStepIndex = Mathf.Max(0, _pingStepIndex - 1);
         Debug.Log($"StepManager: Ping撤销 -> {_pingStepIndex}");
         OnStepChanged?.Invoke(_pingStepIndex);
     }

Assets/Scripts/Core/UndoManager.cs

@@ -30,6 +30,7 @@ public static class ActionHistory
     {
         if (History.Count == 0) return false;
         var item = History.Pop();
+        Debug.Log($"[ActionHistory] Undo {item.Type} handler={(item.Handler != null ? item.Handler.name : "null")}, remaining={History.Count}");
         
         if (item.Type == ActionType.Shose)
         {

Assets/Scripts/Interaction/PingClickHandler.cs

@@ -6,10 +6,9 @@ public class PingClickHandler : MonoBehaviour
     public int pingIndex;
     private MeshRenderer _modelRenderer, _outlineMesh;
     private bool _modelShown;
-    private float _lastClickTime;
-    private bool _isFinished;
+    private bool _isBlinking;
     
-    public bool CanBeClicked() { return !_isFinished; }
+    public bool CanBeClicked() { return _isBlinking; }
 
     void OnEnable()
     {
@@ -19,7 +18,7 @@ public class PingClickHandler : MonoBehaviour
         if (GetComponent<Collider>() == null) gameObject.AddComponent<SphereCollider>().radius = 0.5f;
         CreateOutlineMesh();
         _modelShown = false;
-        _isFinished = false;
+        _isBlinking = true;
         StopAllCoroutines();
         StartCoroutine(BlinkOutline());
     }
@@ -59,9 +58,7 @@ public class PingClickHandler : MonoBehaviour
 
     public void PerformClick()
     {
-        if (Time.time - _lastClickTime < 0.3f) return; // 防连击
-        _lastClickTime = Time.time;
-        if (_isFinished) return;
+        if (!_isBlinking) return; // 防止重复点击
         
         foreach (var c in Object.FindObjectsOfType<Camera>())
         {
@@ -73,6 +70,7 @@ public class PingClickHandler : MonoBehaviour
         if (!_modelShown)
         {
             _modelShown = true;
+            _isBlinking = false;
             ActionHistory.Push(ActionHistory.ActionType.PingFirst, this);
             StopAllCoroutines();
             if (_modelRenderer != null) _modelRenderer.enabled = true;
@@ -127,12 +125,16 @@ public class PingClickHandler : MonoBehaviour
     }
 
     public void ReEnableBorder() { _isBlinking = true; if (_outlineMesh != null) { _outlineMesh.enabled = true; StopAllCoroutines(); StartCoroutine(BlinkOutline()); } }
+
     public void UndoSecondClick() 
     { 
         if (chanraoObject != null) chanraoObject.SetActive(false);
         ShowSelf();
         _modelShown = true; 
-        _isFinished = false;
+        _isBlinking = true;
+        if (_outlineMesh != null) _outlineMesh.enabled = true;
+        StopAllCoroutines();
+        StartCoroutine(BlinkOutline());
     }
     public void UndoShow() { HideSelf(); }
 
@@ -140,7 +142,7 @@ public class PingClickHandler : MonoBehaviour
     {
         foreach (var r in GetComponentsInChildren<Renderer>(true)) r.enabled = false;
         var col = GetComponent<Collider>(); if (col != null) col.enabled = false;
-        _isFinished = true;
+        _isBlinking = false;
         StopAllCoroutines();
     }
 
@@ -154,7 +156,7 @@ public class PingClickHandler : MonoBehaviour
     public void ResetState()
     {
         _modelShown = false;
-        _isFinished = false;
+        _isBlinking = true;
         if (_modelRenderer != null) _modelRenderer.enabled = false;
         // 隐藏自身模型
         foreach (var r in GetComponentsInChildren<Renderer>(true)) { if (_outlineMesh != null && r == _outlineMesh) continue; r.enabled = false; }