Sid AI Agent for Studio Libraries

Add Sid to the Libraries area of Studio so that the whole design of the site can be updated by AI. Ability to give it a design.md file and examples but it still keep the StudioKit (or current library) best practice and things like animations. Simply update the theme (colours, fonts, tailwind variables, custom css etc), settings (head, scripts etc) and sections (create new sections or copy/update existing).