Bug: grady countercharged displays as checky

When I ask it for a grady countercharged (using a grady of sable and white for an example), the countercharged ordinary behaves as if the original pattern was checky. I have tested this with multiple types of ordinaries and multiple directions of gradient, and it appears to be consistently bugged across all of them
_[Grady in annulo sable argent, a chevron countercharged](https://drawshield.net/create/index.html?blazon=grady%20in%20annulo%20sable%20argent%2C%20a%20chevron%20(grady%20in%20annulo%20argent%20sable)%20countercharged)_

Manually overwriting the blazon results in something like this
_[Grady in annulo sable argent, a chevron grady in annulo argent sable](https://drawshield.net/create/index.html?blazon=grady%20in%20annulo%20sable%20argent%2C%20a%20chevron%20grady%20in%20annulo%20argent%20sable%20(countercharged))_
which is a lot closer, but still not quite right. Notably, when using a _grady in annulo_, or radial gradient, the center point of the chevron's gradient is lower than that of the field. When countercharging, it should merely appear to swap the two colors (or in this case reverse the direction of the gradient).

リンクされた grady-in-annulo と countercharged chevron の例で問題を再現し、壊れた出力と手動オーバーライドを比較します。グラデーションと countercharged ordinaries の PHP SVG レンダリングパスを追跡します。完了条件は、報告された方向と ordinary の種類全体で、ordinary が radial-gradient の中心位置を含め、field gradient を正しく反転することです。

索引モデルが issue の本文から書いたものです。