feat: 支付闭环 + 运营助手 Tool Calling + 管理后台完善

- 支付系统：微信支付 mock 自动完成、NATIVE 扫码支付、JSAPI 集成
- 运营助手：Tool Calling 架构，19 个可执行工具，AI 驱动操作
- 角色管理：表格布局 + Dialog 表单 + 权限勾选
- 配置统一：config.ts 单一数据源
- API 审计：补齐 status toggle / comments 端点
- 暗黑模式硬件编码颜色全部替换为 CSS 变量

frontend/src/app/admin/users/page.tsx

@@ -1,6 +1,7 @@
 'use client';
 
 import { useEffect, useState } from 'react';
+import { API_BASE } from '@/lib/config';
 
 interface User {
   id: number;
@@ -27,7 +28,7 @@ export default function UsersPage() {
     try {
       const token = localStorage.getItem('adminToken');
       const params = search ? `?search=${encodeURIComponent(search)}` : '';
-      const res = await fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/admin/users${params}`, {
+      const res = await fetch(`${API_BASE}/admin/users${params}`, {
         headers: { Authorization: `Bearer ${token}` },
       });
       if (res.ok) {
@@ -41,7 +42,7 @@ export default function UsersPage() {
   async function createUser() {
     if (!form.phone || !form.password) return alert('手机号和密码必填');
     const token = localStorage.getItem('adminToken');
-    await fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/admin/users`, {
+    await fetch(`${API_BASE}/admin/users`, {
       method: 'POST',
       headers: { 'Content-Type': 'application/json', Authorization: `Bearer ${token}` },
       body: JSON.stringify(form),
@@ -54,7 +55,7 @@ export default function UsersPage() {
   async function updateUser() {
     if (!editId) return;
     const token = localStorage.getItem('adminToken');
-    await fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/admin/users/${editId}`, {
+    await fetch(`${API_BASE}/admin/users/${editId}`, {
       method: 'PUT',
       headers: { 'Content-Type': 'application/json', Authorization: `Bearer ${token}` },
       body: JSON.stringify({ nickname: form.nickname, email: form.email }),
@@ -68,7 +69,7 @@ export default function UsersPage() {
   async function deleteUser(id: number) {
     if (!confirm('确定删除该用户？')) return;
     const token = localStorage.getItem('adminToken');
-    await fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/admin/users/${id}`, {
+    await fetch(`${API_BASE}/admin/users/${id}`, {
       method: 'DELETE',
       headers: { Authorization: `Bearer ${token}` },
     });
@@ -78,7 +79,7 @@ export default function UsersPage() {
   async function toggleStatus(id: number, currentStatus: string) {
     const token = localStorage.getItem('adminToken');
     const newStatus = currentStatus === 'ACTIVE' ? 'BANNED' : 'ACTIVE';
-    await fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/admin/users/${id}`, {
+    await fetch(`${API_BASE}/admin/users/${id}`, {
       method: 'PUT',
       headers: { 'Content-Type': 'application/json', Authorization: `Bearer ${token}` },
       body: JSON.stringify({ status: newStatus }),