ci: bump Actions off Node 20 runtime (#6)

[chtnnh]

Summary

• Bump actions/checkout / setup-node to v5 across workflows, composite action, and init --workflow
• Also bump Pages (upload-pages-artifact@v5 + include-hidden-files, deploy-pages@v5) so docs deploys stop warning
• Closes Bump GitHub Actions off deprecated Node 20 runtime (checkout/setup-node v4 → v5+) #6

Test plan

• CI green on this PR (no Node 20 action annotations)
• After merge, docs workflow deploy succeeds and .nojekyll is present

[cursor]

PR Summary

Low Risk
Dependency version bumps in CI and docs deploy only; no application or security logic changes.

Overview
Bumps actions/checkout and actions/setup-node from v4 to v5 across all CI workflows (ci, docs, know-code, release, umami-proxy), the composite action/action.yml, know-code init --workflow output, and docs/examples (action/README.md, website/docs/ci.md).

For GitHub Pages, upgrades upload-pages-artifact to v5 and deploy-pages to v5, and sets include-hidden-files: true on the upload step so Docusaurus .nojekyll is included (v4+ drops dotfiles by default).

Tests in commands-core.test.ts now assert generated and checked-in YAML references checkout@v5 and setup-node@v5.

^{Reviewed by Cursor Bugbot for commit 4f2520e. Bugbot is set up for automated code reviews on this repo. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 54a8120. Configure here.}