FLX-4104: Simulation.spec.fidelity names a value this engine does not recognise

Family: governance/sovereignty (the 4000 band)

The FLUX schema's fidelity enum is deterministic/stochastic/agentic; a value outside that set has no execution path in this engine and is refused rather than silently treated as deterministic (which require_supported_fidelity would otherwise do by only checking the two escalated values by name).

Look it up offline

$ fluxsim explain FLX-4104

Every code is listed in the error index.