ReadonlyreasonAn optional machine-readable reason, rendered into the response body alongside the message. DECLARED HERE rather than sniffed structurally at the mapper so the channel is part of the contract a subclass opts into, and so the mapper needs no import of any subclass to render it (see the header for why that import must not exist).
ReadonlystatusThe response status, 4xx or 5xx; any other status answers 500.
The run finished and its summary has aged out of retention. 409 and never a re-execution: a key whose run completed is spent, and the fact that nobody can still read the OUTCOME does not make the WORK un-done.