Deployment prerequisite: merge and deploy https://github.com/simpleanalytics/infrastructure/pull/231 before merging this documentation PR. The corresponding dashboard change, https://github.com/simpleanalytics/dashboard/pull/843, is already merged.

Summary

Fixes #51

Update the custom-domain guide for DNS validation, supported CNAME targets, and automatic certificate issuance. Explain that saving valid DNS starts the HTTPS request, replace the removed inline SSL-checker instructions and screenshot, and clarify script replacement and certificate handling for multiple websites.

The documentation build also exposed a JSX example that Liquid stripped in the React guide. Wrap it in a raw block so the rendered example preserves its ignoreMetrics values.

Security implications

• No security impact
• Has security impact - described as:

Testing

• Synced local master from GitHub through the signed broker; the feature commit includes the current base.
• git diff master...HEAD --check passed.
• JEKYLL_NO_BUNDLER_REQUIRE=true jekyll build --destination /Users/adriaan/Developer/simpleanalytics/.task-tmp/custom-domain-docs-site passed using installed gems: 135 HTML files, no Liquid warnings.
• Verified rendered DNS, certificate, and SSL-checker instructions and the intact React JSX values.
• Checked all related custom-domain documentation references and verified the guide's real links and image URLs.
• Checked the merged dashboard implementation and the infrastructure PR configuration; production rollout was not verified.

Checklist

• Linked to an issue
• Tested
• Asked for a review