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>

components/layout/CookieConsent.tsx

@@ -0,0 +1,65 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import Link from "next/link";
+
+const CONSENT_STORAGE_KEY = "cookie-consent";
+
+export default function CookieConsent() {
+  const [visible, setVisible] = useState(false);
+
+  useEffect(() => {
+    // 仅在浏览器已明确同意/拒绝前展示，避免每次访问重复弹出。
+    const consent = window.localStorage.getItem(CONSENT_STORAGE_KEY);
+    if (!consent) {
+      setVisible(true);
+    }
+  }, []);
+
+  function handleChoice(choice: "accepted" | "rejected") {
+    window.localStorage.setItem(CONSENT_STORAGE_KEY, choice);
+    setVisible(false);
+  }
+
+  if (!visible) {
+    return null;
+  }
+
+  return (
+    <div
+      role="dialog"
+      aria-live="polite"
+      aria-label="Cookie 使用提示"
+      className="fixed inset-x-0 bottom-0 z-[100] border-t border-slate-800 bg-slate-950 px-6 py-4 text-sm text-slate-300"
+    >
+      <div className="mx-auto flex max-w-7xl flex-col items-center justify-between gap-3 sm:flex-row">
+        <p>
+          本网站使用 Cookie 以提升您的浏览体验。继续访问即表示您同意我们按照{" "}
+          <Link
+            href="/privacy-policy"
+            className="underline underline-offset-2 hover:text-white"
+          >
+            隐私政策
+          </Link>{" "}
+          使用 Cookie。您也可以选择拒绝非必要 Cookie。
+        </p>
+        <div className="flex shrink-0 gap-3">
+          <button
+            type="button"
+            onClick={() => handleChoice("rejected")}
+            className="rounded-md border border-slate-600 px-4 py-2 text-slate-300 hover:bg-slate-800"
+          >
+            拒绝
+          </button>
+          <button
+            type="button"
+            onClick={() => handleChoice("accepted")}
+            className="rounded-md bg-primary px-4 py-2 font-medium text-white hover:opacity-90"
+          >
+            接受
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}