Experiment Output Spec
Experiment-app-specific output preferences. Distinct from the shared OutputConfig (which carries analysisName, database policy, report formats — all common across the Single / Scenario / Experiment apps). Lives at the top level of ExperimentConfiguration so the field doesn't pollute the shared OutputConfig with experiment-only concerns.
Currently carries one knob, with room for more per-design-point options when Phase E11 polish lands (per-point CSV reports, per-point configuration overrides, …).