feat: integrate authFetch for API calls in InventoryView and PantryView, and add pantry route with authentication

frontend/app/api/pantry/route.ts

@@ -0,0 +1,13 @@
+import { NextResponse } from 'next/server';
+import { withAuth } from '../../../lib/with-auth';
+
+const API_BASE = process.env.NEXT_PUBLIC_API_URL_INTERNAL || 'http://recipe-api:8080';
+
+export const GET = withAuth(async (_request, session) => {
+  const res = await fetch(`${API_BASE}/api/pantry`, {
+    headers: { Authorization: `Bearer ${session.accessToken}` },
+    cache: 'no-store',
+  });
+  const text = await res.text();
+  return new NextResponse(text, { status: res.status, headers: { 'Content-Type': 'application/json' } });
+});