feat(auth): 用户管理页面过滤纯患者用户 + fix(health): clippy 修复

后端 list_users API 新增 exclude_only_roles 参数，排除仅有指定角色的用户。
前端用户管理页面默认传 'patient' 过滤，wx_* 微信患者不再混入员工列表。
同时修复 erp-health dashboard.rs 的 clippy 警告（unused import + collapsible if）。

apps/web/src/api/users.ts

@@ -18,10 +18,10 @@ export interface UpdateUserRequest {
   version: number;
 }
 
-export async function listUsers(page = 1, pageSize = 20, search = '') {
+export async function listUsers(page = 1, pageSize = 20, search = '', excludeOnlyRoles?: string) {
   const { data } = await client.get<{ success: boolean; data: PaginatedResponse<UserInfo> }>(
     '/users',
-    { params: { page, page_size: pageSize, search: search || undefined } }
+    { params: { page, page_size: pageSize, search: search || undefined, exclude_only_roles: excludeOnlyRoles } }
   );
   return data.data;
 }

apps/web/src/pages/Users.tsx

@@ -52,7 +52,7 @@ export default function Users() {
   const {
     data: users, total, page, loading, refresh,
   } = usePaginatedData<UserInfo>(async (p, pageSize, search) => {
-    const result = await listUsers(p, pageSize, search);
+    const result = await listUsers(p, pageSize, search, 'patient');
     return { data: result.data, total: result.total };
   }, 20);