feat(admin): 独立后台壳、站点分析与聊天监管，公开站拆出主题切换与访问埋点

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/middleware.ts

@@ -129,13 +129,20 @@ function parseCookiePair(setCookie: string): [string, string] | null {
   return [pair.slice(0, eq).trim(), pair.slice(eq + 1).trim()];
 }
 
+/** 透传 pathname 给根布局，用于 /admin 与公开站 chrome 分叉 */
+function withPathname(req: NextRequest, init?: { request?: { headers: Headers } }) {
+  const headers = new Headers(init?.request?.headers ?? req.headers);
+  headers.set("x-pathname", req.nextUrl.pathname);
+  return NextResponse.next({ request: { headers } });
+}
+
 export async function middleware(req: NextRequest) {
   const refreshToken = req.cookies.get(REFRESH_COOKIE)?.value;
   const accessToken = req.cookies.get(TOKEN_COOKIE)?.value;
 
   // 游客、access 仍有效、或服务端地址未配置：直接放行
   if (!refreshToken || !isAccessTokenExpired(accessToken) || !API_BASE) {
-    return NextResponse.next();
+    return withPathname(req);
   }
 
   const csrf = req.cookies.get(CSRF_COOKIE)?.value ?? "";
@@ -154,7 +161,7 @@ export async function middleware(req: NextRequest) {
       const headers = new Headers(req.headers);
       headers.set("Cookie", [...jar].map(([k, v]) => `${k}=${v}`).join("; "));
 
-      const res = NextResponse.next({ request: { headers } });
+      const res = withPathname(req, { request: { headers } });
       // 原样透传，HttpOnly/Path/SameSite/Secure 等属性全部以后端为准
       for (const sc of setCookies) res.headers.append("Set-Cookie", sc);
       return res;
@@ -162,7 +169,7 @@ export async function middleware(req: NextRequest) {
 
     if (setCookies.length > 0) {
       // refresh 已失效：透传后端的清 cookie 指令，避免之后每次请求都白轮转
-      const res = NextResponse.next();
+      const res = withPathname(req);
       for (const sc of setCookies) res.headers.append("Set-Cookie", sc);
       return res;
     }
@@ -170,7 +177,7 @@ export async function middleware(req: NextRequest) {
     // 后端不可达：降级匿名渲染，客户端 fetchWithRefresh 仍可兜底
   }
 
-  return NextResponse.next();
+  return withPathname(req);
 }
 
 export const config = {