Function ballistics_monte_carlo_with_direction_std_dev 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn ballistics_monte_carlo_with_direction_std_dev(
    inputs: *const FFIBallisticInputs,
    atmosphere: *const FFIAtmosphericConditions,
    params: *const FFIMonteCarloParams,
    wind_direction_std_dev: c_double,
) -> *mut FFIMonteCarloResults

Run a Monte Carlo simulation with independent wind-direction uncertainty through the C ABI.

wind_direction_std_dev is in radians. This additive entry point keeps FFIMonteCarloParams and ballistics_monte_carlo binary-compatible; the older function delegates with zero wind-direction uncertainty.

Safety

The pointer and ownership requirements are identical to ballistics_monte_carlo.