bezier strokes don't look good at high curvature

<img width="795" height="282" alt="Image" src="https://github.com/user-attachments/assets/165ddc01-0420-47ea-8d56-1a6282cbf537" />

This is a consequence of my quick & dirty job of converting strokes to filled paths.

Code begins here: https://github.com/audulus/vger/blob/687b78d91b334830e6830008fa6727ffa3cd94a7/Sources/vger/vger.mm#L253