feat: 新增Cookie同意条控件，Footer链接隐私政策

app/layout.tsx

@@ -2,6 +2,7 @@ import type { Metadata } from "next";
 import "./globals.css";
 import Header from "@/components/layout/Header";
 import Footer from "@/components/layout/Footer";
+import CookieConsent from "@/components/layout/CookieConsent";
 import ReactQueryProvider from "@/providers/react-query-provider";
 
 // 面向中国大陆用户，避免依赖 next/font/google（构建期需访问 Google 服务器）。
@@ -23,6 +24,7 @@ export default function RootLayout({ children }: LayoutProps<"/">) {
           <Header />
           <main className="flex-1">{children}</main>
           <Footer />
+          <CookieConsent />
         </ReactQueryProvider>
       </body>
     </html>