Update pixelmatch-cpp to match the current JavaScript implementation

Hi,

I noticed that pixelmatch-cpp appears to be based on an older version of the JavaScript implementation and is no longer fully aligned with the current pixelmatch.

The current JavaScript version is 7.2.0, while the C++ implementation still appears to use the older YIQ-based color-difference metric. The current JavaScript implementation has since moved to OKLab + HyAB for color comparison.

This raises a couple of questions:

Is there a plan to update pixelmatch-cpp to match the current JavaScript implementation?
Is behavioral compatibility between the C++ and JavaScript implementations a goal?
If so, would it be possible to port the newer color-difference algorithm and other changes from the current JavaScript version?
In particular, it would be useful to have the C++ implementation produce the same diff results as the current JavaScript implementation when given the same images and configuration.

I'm interested in using Pixelmatch from a native C++ application without requiring Node.js, so having a current C++ implementation would be very useful.

Thanks!

既存の pixelmatch-cpp 実装と、現在の JavaScript pixelmatch 7.2.0 実装を比較し、まず色差メトリクスに焦点を当てます。OKLab + HyAB およびその他の変更を移植する範囲を明確にします。同じ画像と設定で JavaScript の diff 結果と一致すれば完了とします。