Transition

type Transition =
  | FlowNode
  | (() => FlowNode)
  | {
  data?: Record<string, unknown>;
  goto:   | FlowNode
     | (() => FlowNode);
}
  | {
  handoff: string;
  reason?: string;
}
  | {
  escalate: string;
}
  | {
  end: string;
}
  | "stay";