Follow the guided simulation

The guided simulation shows how a Shutdown Gate moves from current approval to invalidation after a new production consumer appears. It uses a versioned, checked-in fixture. It does not contact DataHub, PostgreSQL, a worker, or an inference provider and does not prove the state of your catalog.

1. Open the guided simulation.
2. On Day 1, inspect the target, replacement, evidence boundary, resolved consumer contract, recorded approval, and Monitoring active state.
3. Move to Day 2. The fixture introduces a new production consumer whose lineage reaches the legacy dataset.
4. Inspect why the prior approval becomes Previous approval invalidated, the affected condition, and the required action.

The fixture demonstrates the UI and deterministic lifecycle contract. To test fresh catalog reads and background monitoring, run Payne locally.