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

Client/Packages/io.github.hatayama.uloopmcp/Editor/Config/ToolDisabledException.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace io.github.hatayama.uLoopMCP
+{
+    /// <summary>
+    /// Thrown when a disabled tool is invoked.
+    /// </summary>
+    public class ToolDisabledException : Exception
+    {
+        public string ToolName { get; }
+
+        public ToolDisabledException(string toolName)
+            : base($"Tool '{toolName}' is disabled")
+        {
+            ToolName = toolName;
+        }
+    }
+}