Write valid `agent-html` DSL pages for this project's preview runtime. Use when Codex needs to compose XML-like preview layouts with `Page`, `Stack`, `Cluster`, `Grid`, and the supported UI tags under `src/agent-html/runtime/ui/*`; use it to draft new pages, adapt existing fixtures, or choose valid Lucide icon names without falling back to JSX, className, or raw HTML.
Use `ahtml` when a semantic `.agent.html` document should be previewed live or exported as an HTML artifact. It fits outputs that need more structure or reviewability than Markdown.