Minimal EAS Build config (development/preview/production profiles) —
needed by `eas credentials` to manage the FCM push key, no EAS Build
runs yet. Push notifications are now fully verified end-to-end: real
device token minted, registered with the backend, and a live push
delivered to the Android emulator's notification tray.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
