Executes an inline draft definition in a zero-side-effect simulator: expressions and transforms run for real, action.call steps are stubbed (fixture > schema-shaped placeholder > empty object) with their evaluated inputs recorded, and waits pause the run unless a fixture resumes them. For event-triggered workflows, pass useLatestEvent: true (or eventId) to replay a stored workflow runtime event through the trigger payload mapping; the simulation fails with "Production would skip this event" when production would not launch the workflow for it. Omit payload and replay to have one synthesized from the trigger event schema or the workflow payload schema (the trigger contract is then not checked). Returns status, a per-step trace, final vars/payload, the stubbed action invocations, and any errors or warnings.