The best demonstration of a CMS for AI agents is a site an agent built. This one was: a coding agent cloned the skeleton, installed AtarCMS with Docker, wrote the owner's answers into a site brief, set up the content model, built this violet theme from a copy of the default one and drafted the texts for the owner to review.
Everything it relied on is public: the skill in .agents/skills/building-atarcms-sites/, HANDBOOK.md and the console's checks. Read How it works to do the same for your site, and check /llms.txt to see what agents read here.