Adds WebGPU support to the Chrome launch args alongside the existing
CanvasDrawElement flag. Use PRODUCER_HEADLESS_SHELL_PATH to point to
Brave for full WebGPU + drawElementImage support.
Also fixes flicker in liquid glass blocks by removing onpaint/requestPaint
callbacks that conflicted with GSAP's deterministic onUpdate rendering.
Adds macos-tahoe-liquid-glass block (WIP).