KiCad 9 defaults to s-expression netlist export, not XML. Add
_parse_kicad_sexp() parser with pinfunction/pintype metadata, update
auto-detection to distinguish (export from <export by content.
Fix export_netlist: use kicad-cli's actual format names (kicadsexpr,
kicadxml) instead of invalid 'kicad', use --format instead of -f, and
treat non-zero exit with valid output as success with warnings.