deviceAuthenticationRotationStatus

This device's server authentication status (docs/device-authentication-rotation.md): the authentication epoch and the server time the registered key was installed at, read from the server with a request signed by the active key (never cached, never stored locally), the key's age by this client's clock (clamped at zero), and whether a rotation or recovery key is pending locally (DeviceAuthenticationRotationStatus.pendingRecovery covers device recovery and last-device recovery). Changes nothing. Throws SecureMessageClientException.NotInitialized without an active key and SecureMessageTransportException.AuthenticationFailed if the active key is not the registered one.