Thrown when the ops an effect handler returns from its completion don't
parse against the stored op schema — a malformed field.* / status.set
(bad type, missing target, wrong value shape). The completion does not
commit; the engine has not mutated state. Mirrors ActionParamsInvalidError:
a handler is external code, so its returned ops are validated at the
completion boundary rather than trusted to be well-formed.
Thrown when the ops an effect handler returns from its completion don't parse against the stored op schema — a malformed
field.*/status.set(badtype, missingtarget, wrongvalueshape). The completion does not commit; the engine has not mutated state. Mirrors ActionParamsInvalidError: a handler is external code, so its returned ops are validated at the completion boundary rather than trusted to be well-formed.