Construct a typed failure with optional native/retry context and local cause.
OptionalcauseReadonlycodeStable failure category for application error handling.
Optional ReadonlynativeNative Valhalla error number, if the failure came from the actor.
ReadonlyretryableTransient failure indicator, not a request to retry indefinitely.
OptionalstackReturn the serializable worker payload; excludes stack and cause.
A typed SDK failure. Retryable errors are transient; retries must remain bounded.