feat(v1): unify API response, validation, exception handling and tests

src/main/resources/static/users.html

@@ -143,7 +143,8 @@ public class UserController {
         // 加载用户列表
         async function loadUsers() {
             const res = await fetch('/api/users');
-            const users = await res.json();
+            const payload = await res.json();
+            const users = payload.data || [];
             const tbody = document.querySelector('#userTable tbody');
             tbody.innerHTML = users.map(u => `
                 <tr>
@@ -196,7 +197,7 @@ public class UserController {
                 await fetch(`/api/users/${id}`, {
                     method: 'PUT',
                     headers: { 'Content-Type': 'application/json' },
-                    body: JSON.stringify({ ...user, id: parseInt(id) })
+                    body: JSON.stringify(user)
                 });
             } else {
                 await fetch('/api/users', {