feat(web): Login/MainLayout 从主题配置读取品牌信息

- Login.tsx 从 /api/v1/public/brand 读取品牌名称/标语/特性/版权
- MainLayout 侧边栏 Logo 和 Footer 从 themeConfig 读取
- 启动时调用 loadThemeConfig 缓存主题配置
- 移除所有硬编码品牌文字（HMR Platform → 动态读取）

apps/web/src/pages/Login.tsx

@@ -1,14 +1,21 @@
+import { useEffect, useState } from 'react';
 import { useNavigate } from 'react-router-dom';
 import { Form, Input, Button, message, Divider } from 'antd';
 import { UserOutlined, LockOutlined, SafetyCertificateOutlined } from '@ant-design/icons';
 import { useAuthStore } from '../stores/auth';
 import ThemeSwitcher from '../components/ThemeSwitcher';
+import { getPublicBrand, type BrandConfig } from '../api/themes';
 
 export default function Login() {
   const navigate = useNavigate();
   const login = useAuthStore((s) => s.login);
   const loading = useAuthStore((s) => s.loading);
   const [messageApi, contextHolder] = message.useMessage();
+  const [brand, setBrand] = useState<BrandConfig | null>(null);
+
+  useEffect(() => {
+    getPublicBrand().then(setBrand);
+  }, []);
 
   const onFinish = async (values: { username: string; password: string }) => {
     try {
@@ -37,9 +44,9 @@ export default function Login() {
             <SafetyCertificateOutlined />
           </div>
 
-          <h1 className="brand-title">HMR Platform</h1>
-          <p className="brand-desc">新一代健康管理平台</p>
-          <p className="brand-sub-desc">慢病跟踪 · 工作流引擎 · 消息中心 · 系统配置</p>
+          <h1 className="brand-title">{brand?.brand_name || 'HMS 健康管理平台'}</h1>
+          <p className="brand-desc">{brand?.brand_slogan || '新一代健康管理平台'}</p>
+          <p className="brand-sub-desc">{brand?.brand_features || '患者管理 · 健康监测 · 随访管理 · AI 智能分析'}</p>
 
           <div style={{ marginTop: 48, display: 'flex', gap: 32, justifyContent: 'center' }}>
             {[
@@ -103,7 +110,7 @@ export default function Login() {
           </Form>
 
           <div className="form-footer">
-            HMR Platform · ©汕头市智界科技有限公司
+            {brand?.brand_copyright || 'HMS 健康管理平台 · ©汕头市智界科技有限公司'}
           </div>
         </div>
       </main>