fix: add missing using statement for MCPForUnityEditorWindow

Add 'using MCPForUnity.Editor.Windows;' to resolve unresolved symbol error for MCPForUnityEditorWindow in SetupWizard.cs

Author: Claude

UnityMcpBridge/Editor/Setup/SetupWizard.cs

@@ -2,6 +2,7 @@
 using MCPForUnity.Editor.Dependencies;
 using MCPForUnity.Editor.Dependencies.Models;
 using MCPForUnity.Editor.Helpers;
+using MCPForUnity.Editor.Windows;
 using UnityEditor;
 using UnityEngine;