The previous script generated a 1024x1024 icon from the SVG with no
squircle background and no transparent padding, which caused macOS
to render the Dock/Finder icon noticeably larger than first-party
apps and without the rounded-square shape users expect.
Rewrite the script to follow Apple's Big Sur+ icon template:
- 1024x1024 canvas
- 824x824 white squircle, centered (100px transparent padding outside)
- Artwork rendered at 560x560, centered inside the squircle
- Squircle corner radius ~22.5% of the squircle size
Use rsvg-convert to rasterize the SVG (ImageMagick crops this
particular SVG when rendering directly), then composite onto the
squircle background in two steps for reliability.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
