feat(middleware): migrate authentication logic from middleware.ts to proxy.ts

frontend/proxy.ts

@@ -0,0 +1,33 @@
+import { NextResponse } from 'next/server';
+import { auth } from './auth';
+
+export default auth((req) => {
+  const { pathname } = req.nextUrl;
+
+  // Alltid tillgängliga sidor
+  const publicPaths = ['/login', '/register'];
+  if (publicPaths.some((p) => pathname.startsWith(p))) {
+    return NextResponse.next();
+  }
+
+  // Om ej inloggad, omdirigera till /login
+  if (!req.auth) {
+    const loginUrl = new URL('/login', req.url);
+    loginUrl.searchParams.set('callbackUrl', pathname);
+    return NextResponse.redirect(loginUrl);
+  }
+
+  // Admin-sidor kräver admin-roll
+  if (pathname.startsWith('/admin')) {
+    const role = (req.auth.user as any)?.role;
+    if (role !== 'admin') {
+      return NextResponse.redirect(new URL('/', req.url));
+    }
+  }
+
+  return NextResponse.next();
+});
+
+export const config = {
+  matcher: ['/((?!_next/static|_next/image|favicon.ico|api/auth).*)'],
+};