One reason a plan is not executable. Static — no database was consulted.On the wire, in ErrorBody.error.details.refusals: a rejected composition answers 400 with
ALL of these at once, never just the first, because repairing a plan one refusal per round trip
is the experience that design avoids. It carries the generation derives for that reason — it
went without them while nothing could return it, and a door is now being built that does.
{
"detail": "string",
"reason": "unsupported_bound_kind",
"stage": null
}