fix: 修复WorkflowPageV3组件TypeScript错误和清理副本文件

详细说明:
- 修复WorkflowPageV3.tsx中的TypeScript类型错误
- 移除未使用的executionTimeoutRef变量
- 修复style标签的jsx属性问题
- 将deprecated的substr()改为substring()
- 清理n8n目录下的副本文件
- 添加server.js和start脚本用于静态文件服务

影响的文件:
- web_frontend/exhibition-demo/src/pages/WorkflowPageV3.tsx
- web_frontend/exhibition-demo/src/components/ResultModal.tsx
- web_frontend/web_result/server.js (新增)
- web_frontend/web_result/start.bat (新增)
- web_frontend/web_result/start.sh (新增)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

web_frontend/exhibition-demo/src/components/ResultModal.tsx

@@ -141,15 +141,13 @@ const ResultModal: React.FC<ResultModalProps> = ({ isOpen, onClose, onViewDetail
 
                 {/* 操作按钮 */}
                 <div className="flex gap-3">
-                  <a
-                    href="../web_result/index.html"
-                    target="_blank"
-                    rel="noopener noreferrer"
+                  <button
+                    onClick={() => window.open('http://localhost:4155', '_blank')}
                     className="flex-1 px-6 py-3 bg-gradient-to-r from-blue-600 to-purple-600 text-white rounded-xl font-medium hover:shadow-lg transform hover:scale-105 transition-all flex items-center justify-center gap-2"
                   >
                     <Eye className="w-5 h-5" />
                     查看详细方案
-                  </a>
+                  </button>
                   <button
                     className="flex-1 px-6 py-3 bg-gray-100 text-gray-700 rounded-xl font-medium hover:bg-gray-200 transition-colors flex items-center justify-center gap-2"
                   >