Architecture and boundaries

Keeps an Expo app in a provable shape: every file has one home in the src/ layout, dependencies point one way along declared zones, src/core is pure, every side effect sits behind a port with an adapter and an in-memory fake, one composition root creates the adapters, and nothing runs at import time. Two zero-dependency checkers prove it on every change, on resolved imports, for iOS and Android alike.

Rules that must hold