OptionalagentRun?: { ErrorMessage?: string }OptionalerrorMessage?: stringOptionalrequestAcknowledged?: booleanTrue when the fire-and-forget mutation returned an ACK before the transport died. False when the request never left the browser (or the ACK never arrived). Undefined for callers that do not know.
Prefer the persisted run's ErrorMessage, then a transport-level errorMessage. Never returns empty string.