Compresses PNG and JPEG screenshots in place using pngquant and jpegoptim, which are purpose-built for UI content with flat colors and text. The deliberate choice to stick with PNG/JPEG instead of converting to WebP is about compatibility: WeChat editors, Word, PowerPoint, and various CMSes still choke on WebP. You get 60-80% size reduction on PNGs and 20-50% on JPEGs, which is usually enough for documentation images without the format headaches. The script won't auto-install dependencies, it just tells you the brew or apt command and exits, which is the right call for a system-level tool.
npx skills add https://github.com/zc277584121/marketing-skills --skill screenshot-compression