GitHub sometimes returns transient 502 errors for valid URLs,
causing false positives in CI markdown link checks.
Co-authored-by: Claude <noreply@anthropic.com>
iso.org blocks automated HTTP requests with 403 Forbidden.
Also update the ISO 30170 URLs to current format in README.md
and CONTRIBUTING.md.
Co-authored-by: Claude <noreply@anthropic.com>