Register CreatePrefabTool in Unity server

Modified McpUnityServer.cs to register the new CreatePrefabTool in the tool list, enabling it to be recognized and used by the MCP Unity Editor.

Author: CoderGamester

Editor/UnityBridge/McpUnityServer.cs

@@ -249,6 +249,10 @@ private void RegisterTools()
             // Register AddAssetToSceneTool
             AddAssetToSceneTool addAssetToSceneTool = new AddAssetToSceneTool();
             _tools.Add(addAssetToSceneTool.Name, addAssetToSceneTool);
+            
+            // Register CreatePrefabTool
+            CreatePrefabTool createPrefabTool = new CreatePrefabTool();
+            _tools.Add(createPrefabTool.Name, createPrefabTool);
         }
 
         /// <summary>