Design This skill is a local build of the claude.ai Design (canvas) artifact type: the rules below are the type's own, with the Artifact tool replaced by files on disk and this skill's (The calls). A canvas is a folder, ; its content is ITS OWN files under . The editor page ( , served by ) reads those files and saves the user's edits back into them. Write only under : a file elsewhere never shows. The canvas exists Work on THAT canvas, its in every command: never create another. If no canvas exists yet: = a new folder named for the canvas ( ) in the working directory, or where the user says;…