fix: use canonical Auth.js session in proxy

src/proxy.ts

@@ -1,21 +1,14 @@
-import { type NextRequest, NextResponse } from "next/server";
-import { getToken } from "next-auth/jwt";
-import { authSessionCookieName, shouldRedirectAdminRequest } from "@/lib/proxy-access";
+import { NextResponse } from "next/server";
+import { auth } from "@/lib/auth";
+import { shouldRedirectAdminRequest } from "@/lib/proxy-access";
 
 // Edge proxy (formerly "middleware"): Prisma can't run here, so we only forward
 // the request path (so server components / the access guard can read it via
 // headers()) and normalize the real client IP. The DB-backed banned/maintenance
 // checks happen in src/lib/access-guard.ts (Node runtime) from the root layout.
-export async function proxy(req: NextRequest) {
-  if (req.nextUrl.pathname === "/admin" || req.nextUrl.pathname.startsWith("/admin/")) {
-    const secret = process.env.AUTH_SECRET;
-    const cookieName = authSessionCookieName(req.cookies.getAll().map((cookie) => cookie.name));
-    const token = secret && cookieName
-      ? await getToken({ req, secret, cookieName })
-      : null;
-    if (shouldRedirectAdminRequest(req.nextUrl.pathname, token)) {
-      return NextResponse.redirect(new URL("/login", req.url));
-    }
+export const proxy = auth((req) => {
+  if (shouldRedirectAdminRequest(req.nextUrl.pathname, req.auth?.user ?? null)) {
+    return NextResponse.redirect(new URL("/login", req.url));
   }
 
   const headers = new Headers(req.headers);
@@ -27,7 +20,7 @@ export async function proxy(req: NextRequest) {
     "";
   if (ip) headers.set("x-real-client-ip", ip);
   return NextResponse.next({ request: { headers } });
-}
+});
 
 export const config = {
   matcher: ["/((?!api|_next/static|_next/image|assets|favicon.ico).*)"],