FLX-4003: decision record does not satisfy the RFC-04 decision contract

Family: governance/sovereignty (the 4000 band)

A decision was about to be recorded to decisions.ndjson but it does not validate against flux-enforcement-0.5.0.json#/$defs/decision -- the schema every conformant gate's output must satisfy. This should be unreachable for a decision produced by flux_engine.spec.enforce.decide; seeing it means a caller constructed or mutated a decision object by hand before recording it.

Look it up offline

$ fluxsim explain FLX-4003

Every code is listed in the error index.