fix: resolve remaining clippy warnings and improve workflow frontend

- Collapse nested if-let in user_service.rs search filter
- Suppress dead_code warning on ApiDoc struct
- Refactor server routing: nest all routes under /api/v1 prefix
- Simplify health check route path
- Improve workflow ProcessDesigner with edit mode and loading states
- Update workflow pages with enhanced UX
- Add Phase 2 implementation plan document

apps/web/src/pages/workflow/ProcessDefinitions.tsx

@@ -4,6 +4,7 @@ import type { ColumnsType } from 'antd/es/table';
 import {
   listProcessDefinitions,
   createProcessDefinition,
+  updateProcessDefinition,
   publishProcessDefinition,
   type ProcessDefinitionInfo,
   type CreateProcessDefinitionRequest,
@@ -57,14 +58,19 @@ export default function ProcessDefinitions() {
     }
   };
 
-  const handleSave = async (req: CreateProcessDefinitionRequest) => {
+  const handleSave = async (req: CreateProcessDefinitionRequest, id?: string) => {
     try {
-      await createProcessDefinition(req);
-      message.success('创建成功');
+      if (id) {
+        await updateProcessDefinition(id, req);
+        message.success('更新成功');
+      } else {
+        await createProcessDefinition(req);
+        message.success('创建成功');
+      }
       setDesignerOpen(false);
       fetch();
     } catch {
-      message.error('创建失败');
+      message.error(id ? '更新失败' : '创建失败');
     }
   };