chore(unity): 固定Unity CLI Loop本地包并移除UnitySkills依赖

Client/Packages/io.github.hatayama.uloopmcp/Editor/Api/McpTools/SimulateMouseUi/MouseDragState.cs

@@ -0,0 +1,38 @@
+#nullable enable
+using UnityEditor;
+using UnityEngine;
+using UnityEngine.EventSystems;
+
+namespace io.github.hatayama.uLoopMCP
+{
+    // Tool instances are created fresh per invocation, so drag state
+    // between DragStart/DragMove/DragEnd must be held statically.
+    [InitializeOnLoad]
+    internal static class MouseDragState
+    {
+        internal static bool IsDragging => Target != null && PointerData != null;
+        internal static GameObject? Target { get; set; }
+        internal static PointerEventData? PointerData { get; set; }
+
+        static MouseDragState()
+        {
+            // PlayMode exit leaves dangling references to destroyed GameObjects
+            EditorApplication.playModeStateChanged += OnPlayModeStateChanged;
+        }
+
+        internal static void Clear()
+        {
+            Target = null;
+            PointerData = null;
+        }
+
+        private static void OnPlayModeStateChanged(PlayModeStateChange state)
+        {
+            if (state == PlayModeStateChange.ExitingPlayMode)
+            {
+                Clear();
+                SimulateMouseUiOverlayState.Clear();
+            }
+        }
+    }
+}