Expo & EAS: shipping React Native

Scope. This skill owns the Expo platform: router, config plugins, EAS, native modules, store builds. Animation and gestures (Reanimated worklets, sheets, press feedback, haptics) follow ../react-native/SKILL.md. Visual design of web pages and screens is ../design/SKILL.md's.

What this skill owns

Expo is the toolchain and EAS cloud platform layered on React Native: cloud builds, store submission, over-the-air JS updates, and native configuration declared in JavaScript instead of hand-edited Xcode/Gradle projects. This skill owns the shipping pipeline and native-config-via-JS.