Function pio_dist_summary_json 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pio_dist_summary_json(
    net: *const PioDistNetwork,
    errbuf: *mut c_char,
    errlen: usize,
) -> *mut c_char

Serialize a compact summary of a distribution handle as JSON. This lets bindings answer display and scalar queries without forcing pio_dist_to_json’s full model payload.