Drop and replay an asynchronous artifact event

Goal: observe how an agent handles a missing or duplicate artifact update.

Use the local exercise before placing AIT on a production stream:

ait lab start --exercise asynchronous-artifact

Drop revision r1, replay revision r2, and compare total deliveries with the subscriber's unique-ID ledger.

1. Place AIT on the A2A SSE, WebSocket, or gRPC connection.
2. Break on the artifact identifier or update operation.
3. Trigger the asynchronous task and select its paused artifact event.
4. Choose Drop to test missing-update handling.
5. Repeat from a clean task and choose Duplicate to send two correlated copies.
6. Follow request, stream, task, artifact, and callback links in the history.

The event decision and receiver response are evidence. A downstream impact is only proven when an out-of-band source records the controlled effect.