feat(flow): 添加动态API路由支持通过流程code执行

refactor(engine): 优化节点执行耗时记录
fix(db): 修正结果模式获取逻辑忽略connection.mode
style(i18n): 统一节点描述和输出模式选项的国际化
test(flow): 新增测试流程定义文件
refactor(react): 简化开发环境日志降噪处理

backend/test_flow_create.json

@@ -0,0 +1,5 @@
+{
+  "name": "测试流程",
+  "code": "test-flow",
+  "yaml": "# demo flow\nnodes:\n  - { id: start, kind: start, name: 开始 }\n  - { id: assign, kind: custom, name: 赋值, script: ctx.x = ctx.input.name || 'default'; }\n  - { id: end, kind: end, name: 结束 }\nedges:\n  - { from: start, to: assign }\n  - { from: assign, to: end }\n"
+}