fix proxy.ts: use named export instead of default export

Next.js 16 requires a named `proxy` export, not a default export.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: prazgaitis

apps/web/proxy.ts

@@ -1,8 +1,8 @@
 import { NextResponse } from "next/server";
 
 // Better Auth handles authentication via cookies
-// No middleware protection needed - routes are protected at the page/API level
-export default function proxy() {
+// No proxy protection needed - routes are protected at the page/API level
+export function proxy() {
   return NextResponse.next();
 }