Agent Skills: page-serve

Hand a human a rendered HTML page at a stable HTTPS URL. Registers a portless route for a file or directory (https://NAME.localhost/, never a :port), prints the URL, optionally screenshots it through agent-browser, and tears it down on stop. Use whenever an agent has produced a page a human is meant to open: glyph explainers, playgrounds, decision pages, visualize-plan output, a docs preview. Replaces the ad hoc python http.server plus hand-typed alias pattern that leaves servers alive across sessions.