Function wind_truing_json_value 

pub fn wind_truing_json_value(
    report: &WindTruingReport,
    units: UnitSystem,
) -> Value

The wind-truing report as a JSON document (MBA-1392).

Split out from format_wind_truing_report so the conditional fields (the optional sigma, called wind and correction factor, which are null when absent) are testable on the host — wasm.rs is wasm32-gated, so a formatter that only existed inside it could never be asserted against natively. Same reason drag_coefficient_json_value exists.