fix(utils): 添加空数据检查避免转换空的流程数据

src/utils/convertFlowData.ts

@@ -7,6 +7,8 @@ export const convertFlowData = (flowData: any) => {
   const nodes: any[] = [];
   const edges: any[] = [];
 
+  if (!flowData || Object.keys(flowData).length === 0) return { nodes, edges };
+
   // 处理节点配置
   const nodeConfigs = flowData.main?.nodeConfigs || [];
   for (const nodeConfig of nodeConfigs) {