ci: add CNAME for docs.agentos.sh custom domain

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: jddunn

.github/workflows/docs.yml

@@ -95,6 +95,9 @@ jobs:
           # Create .nojekyll to prevent GitHub Pages from ignoring _* files
           touch docs-deploy/.nojekyll
 
+          # Create CNAME for custom domain
+          echo "docs.agentos.sh" > docs-deploy/CNAME
+
       - name: Deploy to agentos-live-docs branch
         uses: peaceiris/actions-gh-pages@v4
         with: