ci(docs): publish static docs to asystem

[xsuler]

Summary

• build Sphinx docs with warnings treated as errors
• publish compiled docs to inclusionAI/asystem under docs/areno
• support an empty asystem repo and add .nojekyll at the Pages roots so Sphinx static assets are served

Verification

• source ~/miniconda/etc/profile.d/conda.sh && conda activate share && rm -rf dist/docs && python -m sphinx -W --keep-going -b html -D html_copy_source=0 docs dist/docs

[gemini-code-assist]

Note

Gemini is unable to generate a review for this pull request due to the file types involved not being currently supported.

[adohe]

/lgtm