OptionalmaxOptionalonCalled on stage transitions and after each poll with updated progress.
OptionalpollInitial interval between polls. Default 500ms, backed off up to maxPollIntervalMs.
OptionalsignalAbort the workflow. Cancels the current poll and calls cancelBacktest server-side if execution has started.
OptionaltimeoutPer-stage timeout. Default none.
Upper bound for exponential backoff. Default 5000ms.