/** @type {import('next').NextConfig} */
const nextConfig = {
  reactStrictMode: true,
  output: "standalone",
  serverExternalPackages: ["mongodb"],
  async headers() {
    // The page shell must NEVER be cached: hashed chunk filenames change every
    // build, and a stale HTML pins the browser to chunk hashes that no longer
    // exist -> hydration dies and the skeleton hangs forever (learned on
    // forthena 2026-08-30). Static assets keep immutability.
    return [
      {
        source: "/",
        headers: [{ key: "Cache-Control", value: "no-cache, no-store, must-revalidate" }],
      },
      {
        source: "/api/:path*",
        headers: [{ key: "Cache-Control", value: "no-store" }],
      },
      {
        source: "/_next/static/:path*",
        headers: [{ key: "Cache-Control", value: "public, max-age=31536000, immutable" }],
      },
    ];
  },
};

module.exports = nextConfig;