- Created app directory with new root layout combining _app and _document
- Converted all pages from pages/ to app/ directory structure
- Updated routing from next/router to next/navigation hooks
- Marked client components with 'use client' directive
- Split gateway.ts to handle client/server concerns separately
- Converted getStaticProps/getStaticPaths to Server Components and generateStaticParams
- Updated all dynamic routes to new [param] folder structure
- Fixed type issues with Post and Author types
- Updated authentication and navigation components for App Router

All routes successfully converted:
- Home page (/)
- Blog pages (/posts, /posts/[slug])
- Auth pages (/signin, /signup, /signup-confirm)
- Protected pages (/admin, /profile)
- Feature pages (/todomvc, /bookings-auto, /bookings-custom, /shadcn-ui, /features)
- Error pages (/forbidden)

Note: Static export has a runtime issue during build that needs investigation