Migrate this Next.js project from Pages Router to App Router. The project currently uses the pages directory structure with two pages (index and about). You need to:

1. Create the app directory with the proper App Router structure
2. Migrate the pages from pages/ to app/ (index → app/page.tsx, about → app/about/page.tsx)
3. Create a root layout file (app/layout.tsx) with proper HTML structure and shared metadata
4. Remove the pages directory and any pages-specific files
5. Update imports and routing patterns to use App Router conventions
6. Ensure the migrated app builds and runs correctly

Keep the same functionality and UI, but use App Router patterns and file structure.
