Add Site GitHub Actions workflow running prettier format check, astro
check, tests, and build on changes under site/. Wire prettier into the
site package with config, ignore, and scripts, and format existing
sources.
Add install.ps1 mirroring install.sh for Windows: arch detection,
release zip download, binary extraction, user PATH update.
- copy install.ps1 to site public/ at build time (copy-install.mjs)
- serve /install.ps1 with text/plain Content-Type (vercel.json)
- add PowerShell one-liner to install page and README
- bump install.ps1 default version in bump_version.sh
- add CopyButton component next to every install command line
