Function self_intersections_handle_native 

pub fn self_intersections_handle_native(
    handle: u32,
    chord_tolerance: f64,
) -> Result<SelfIntersectionReport, String>

Face-versus-face self-intersection of a resident solid — the OTHER check validate() does not make (its one “self-intersects” string is a uv-wire warning). Opt-in and expensive: it tessellates the solid and walks a triangle BVH, so no default gate calls it. chord_tolerance overrides the per-solid display density when positive. Reads the solid in one registry borrow.