feat: 初始化义工时长管理系统

- 管理台：活动设置、时长登记、用户管理、数据导出（Excel/PNG）
- 用户端：姓名查询个人义工时长与活动记录
- 技术栈：React + Vite + TailwindCSS / Node.js + Express + sql.js (SQLite)
- 支持 Docker 部署，附带 Gitea Actions 自动部署工作流
- 响应式界面，兼容移动端与 PC 端
- 默认管理员账号：admin / admin123

client/src/App.tsx

@@ -0,0 +1,28 @@
+import { Routes, Route, Navigate } from 'react-router-dom';
+import UserIndex from './pages/user/Index';
+import UserDashboard from './pages/user/Dashboard';
+import AdminLogin from './pages/admin/Login';
+import AdminLayout from './pages/admin/Layout';
+import Activities from './pages/admin/Activities';
+import Hours from './pages/admin/Hours';
+import Users from './pages/admin/Users';
+import Export from './pages/admin/Export';
+
+export default function App() {
+  return (
+    <Routes>
+      <Route path="/" element={<Navigate to="/u" replace />} />
+      <Route path="/u" element={<UserIndex />} />
+      <Route path="/u/:id" element={<UserDashboard />} />
+      <Route path="/admin/login" element={<AdminLogin />} />
+      <Route path="/admin" element={<AdminLayout />}>
+        <Route index element={<Navigate to="activities" replace />} />
+        <Route path="activities" element={<Activities />} />
+        <Route path="hours" element={<Hours />} />
+        <Route path="users" element={<Users />} />
+        <Route path="export" element={<Export />} />
+      </Route>
+      <Route path="*" element={<Navigate to="/u" replace />} />
+    </Routes>
+  );
+}