描述
Build Next.js 16 apps with App Router, Server Components/Actions, Cache Components ("use cache"), and async route params. Includes proxy.ts and React 19.2. Prevents 25 documented errors. Use when: building Next.js 16 projects, or troubleshooting async params (Promise types), "use cache" directives, parallel route 404s, Turbopack issues, i18n caching, navigation throttling.