Secrets-019: the hub channels are created with ThrowOperationCanceledOnCancellation = true, so a
call cancelled through its token throws OperationCanceledException. Defensively, the failover
reader rethrows RpcException(Cancelled)-with-a-cancelled-token as cancellation instead of dialing
every fallback with the same cancelled token, and the sweep treats it as shutdown, not a failure
recorded in ISecretsHubSyncStatus. A server-side Cancelled status (token not cancelled) still fails
over.
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
Joseph Doherty