Function sharp_core 

pub(crate) fn sharp_core(
    field: &[f64],
    mask: &[u8],
    grid: &Grid,
    threshold: f64,
    radius: f64,
) -> (Vec<f64>, Vec<u8>)

QSM.jl’s SHARP (SharpVariant::QsmJl) with an explicit kernel radius (mm).

Internal entry point shared with V-SHARP; the public sharp wrapper dispatches to it for SharpVariant::QsmJl.