Expo Router

File-based routes, `_layout`, and the mental model vs React Navigation.

Push/pop, headers, and screen options in `app/` directories.

Tab bars, drawer gestures, and nested layout composition.

`(auth)`, `(tabs)`, and private folder conventions.

Declarative navigation and prefetch-friendly links.

Generated types and safe param passing between screens.

Default landing screens and auth-gated entry points.

Keep route files thin; logic lives in features.