ci: add GitHub Pages pull request previews

[isaaclins]

What changed

• Publish the Hugo production build to gh-pages with JamesIves/github-pages-deploy-action.
• Preserve pr-preview/ during production deploys with clean-exclude: pr-preview/, single-commit: false, and force: false.
• Add static/CNAME with the exact contents isaaclins.com.
• Build pull request previews with rossjrw/pr-preview-action at https://isaaclins.com/pr-preview/pr-<number>/ and remove them when the pull request closes.
• Document the Pages source and CNAME requirements.

Cutover sequence

1. Merge this pull request.
2. Confirm the gh-pages branch is populated by pages-deploy and its root CNAME contains isaaclins.com.
3. Flip the GitHub Pages source to deploy from the gh-pages branch at the repository root.
4. Verify that https://isaaclins.com/ still serves the production site.
5. Only then expect new or updated pull requests to receive previews.

This pull request does not change the GitHub Pages setting. It must remain workflow until the branch deployment is populated and checked.

[Copilot]

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[github-actions]

PR Preview Action v1.8.1
Preview removed because the pull request was closed.
2026-08-05 07:08 UTC