Mobile Auth (Better Auth + Expo)

The mobile app uses Better Auth with @better-auth/expo plugin.

The Problem

Better Auth's session state doesn't sync reliably with React context on Expo. The plugin stores cookies in expo-secure-store, but reactive session updates don't propagate as expected.

Our Solution

Custom SessionProvider that:

1. Initializes from cache - Read cached session from SecureStore on app start
2. Subscribes to auth signals - Listen to $sessionSignal for auth state changes
3. Manual refresh - Call onAuthSuccess() after sign-in/sign-up

Reading Cached Session