- Add FFI wrappers for all EskinDeviceFunc trait methods:
eskin_read_hdw_version, eskin_read_matrix_row/col,
eskin_read_device_config1/2, eskin_write_device_config1/2,
eskin_write_matrix_row/col
- Extract sdk_error_to_code() helper for SdkError -> SdkErrorCode conversion
- Update C header (include/eskin_ffi.h) with new function declarations
- Update Python FFI bindings (example/python/eskin_ffi.py) with new methods
- Update README with Python usage instructions and full FFI interface table