feat(dist): AUR publish workflow + aur-package mirror

[ulises-jeremias]

Summary

Wire AUR distribution parity with Create-Node-App:

• Seed Create-Python-App/aur-package with PKGBUILD for PyPI sdist
• Implement publish-aur.yml (bump pkgver/sha256, push via github-actions-aur-publish)
• Document AUR_SSH_PRIVATE_KEY + AUR_REPO_TOKEN
• Extend smoke-distribution.yml

CNA mapping

Create-Node-App/aur-package + publish-aur.yml