Generate front-end UI specifications, code, and a framework-agnostic Design Source of Truth (design.md) for Web, GUI, or Terminal interfaces through a constraint-aware 9-phase workflow with structural anti-skip enforcement. Uses Execute-Verify-Record pattern at every step to prevent token optimization bias. Supports Web (React, Blazor, ASP.NET, HTML), Desktop GUI (WPF, Tkinter), and Terminal interfaces. Produces design.md — a single document from which ANY AI can recreate the complete UI in any framework. Supports three modes: generated (interactive discovery), extracted (from existing mockup code via --extract), and hybrid. Validates context files, respects architectural constraints, and interactively guides users through technology and styling decisions. Use when stories require UI components, when generating visual specifications from requirements, or when extracting a design source of truth from existing mockups. Always use this skill when the user runs /create-ui.