ReadonlytoMaps an opened session to the principal it carries. Return null when
the session holds no identity — the strategy chain then continues.
Synchronous and session-only, so it cannot re-check the account on each
request. For that, record the principal through signIn: { providers: [] }
and configure refreshPrincipal and sessionStamp.
Session authentication configuration options.
The session payload is application data, so the framework picks no conventional key:
toPrincipalis the one place that knows where an identity lives inside the payload, and it is required.Since
0.1.0