chore(init): 初始化解忧商行项目并完成 Phase 0 基座

frontend/src/app/AppRouter.tsx

@@ -0,0 +1,22 @@
+import { Route, Routes } from 'react-router-dom'
+
+import { AdminPlaceholderPage } from '@/features/admin/AdminPlaceholderPage'
+import { LoginPage } from '@/features/auth/LoginPage'
+import { ListingListPage } from '@/features/listings/ListingListPage'
+import { NotFoundPage } from '@/features/NotFoundPage'
+import { StorefrontLayout } from '@/layouts/StorefrontLayout'
+
+export function AppRouter() {
+  const adminBase = import.meta.env.VITE_ADMIN_BASE_PATH || '/console-jy8k3m'
+
+  return (
+    <Routes>
+      <Route element={<StorefrontLayout />}>
+        <Route index element={<ListingListPage />} />
+      </Route>
+      <Route path="/login" element={<LoginPage />} />
+      <Route path={`${adminBase}/*`} element={<AdminPlaceholderPage />} />
+      <Route path="*" element={<NotFoundPage />} />
+    </Routes>
+  )
+}