Mobile push

The mobile app registers an Expo push token once someone signs in. The API pushes:

• every transmission in direct links and meshes;
• mentions in beacons;
• incoming calls.

Nobody gets a push for:

• conversations or beacons they muted, or with mobile push turned off;
• anything while they are in Do Not Disturb;
• their own transmissions.

Encrypted conversations push only "Sent an encrypted transmission", because the server cannot read them. Tokens Expo reports as no longer registered are deleted.

Setup

1. Create an Expo project for your build of apps/mobile (eas init); this sets extra.eas.projectId in app.json.
2. Configure credentials for the stores (eas credentials): APNs for iOS, FCM for Android.
3. If you turn on enhanced push security for the project, set EXPO_ACCESS_TOKEN in .env.

Pushes are sent to https://exp.host/--/api/v2/push/send (override with EXPO_PUSH_URL, which the tests use).