Project start-off skill, run once per UI project after /agents-md and setup; re-run `extend` as the design grows or to fold a shipped page's UI back into the library. Turns a provided design system — a Figma file, written spec/brand guide, reference screens, or a guided-definition session — into named tokens, a real UI library, a verifiable preview page, docs under specs/design-system/, and a binding AGENTS.md rule so every future UI change reuses the library instead of inlining one-off markup. Stack-adaptive — reads each project's stack from the workspace matrix that /agents-md generates. A design-system source is required — never fabricated. Never auto-chains.
