feat: enhance CORS configuration and implement throttling for API endpoints; add admin role checks in controllers

frontend/middleware.ts

@@ -0,0 +1,19 @@
+import { auth } from './auth';
+import { NextResponse } from 'next/server';
+
+export default auth((req) => {
+  const { pathname } = req.nextUrl;
+
+  if (pathname.startsWith('/admin')) {
+    const role = (req.auth?.user as any)?.role;
+    if (role !== 'admin') {
+      const loginUrl = new URL('/login', req.url);
+      loginUrl.searchParams.set('callbackUrl', pathname);
+      return NextResponse.redirect(loginUrl);
+    }
+  }
+});
+
+export const config = {
+  matcher: ['/admin/:path*'],
+};