mobile-nav-plan: Navigation Architecture, Nothing Else

Navigation is information architecture. This skill produces a Nav Read - a committed route tree that doubles as the Expo Router app/ directory plan - and stops. No screen code.

The method lives in ../_shared/references/navigation.md (container decision tree, Expo Router conventions, mechanical checks, three worked examples). Tells cited by number (#24 etc.) live in ../_shared/references/tells.md. Read both in full before producing the Nav Read.

Flow