recordResponse abstract method
Attach the response a completed execution produced, so a later duplicate can be answered with it per §7.2 (Disposition of a duplicate) rather than merely absorbed in silence.
A guard that records nothing still satisfies item 11 — the effect does not happen twice — and is the right shape for a fire-and-forget specification, which has no response to return.
Implementation
Future<void> recordResponse(String id, Object? response);