ADR 0003: Make session storage widget-readable

Status: accepted

Decision

Implement the token vault as a reusable native component and store a versioned, platform-neutral session record.

On iOS, sharing is opt-in through a Keychain/App Group. On Android, widgets in the same application package use the same vault.

Consequences

• Adding a widget later does not require migrating out of app-only storage.
• A widget can read the current session in v1.
• The canonical OIDC user record and native widget snapshot are separate writes. The snapshot is an eventually consistent cache, so widgets must tolerate an absent or temporarily stale value.
• Native widget refresh is explicitly deferred.