描述
Produces a design-plan (living document like an exec-plan) that maps an app domain to feature groups using Apple Design DNA patterns. Each feature group becomes a milestone buildable in one ios-taste session. Use when the user describes an app idea, domain, or workflow and needs a structured plan before building. Triggers on "plan this app", "what features does X need", "design plan", "feature breakdown", "what screens do I need", or any pre-build planning question. Also trigger when the user provides workflow notes or user interview results. CRITICAL: This skill produces a DESIGN-PLAN document only. It does NOT generate SwiftUI code, layouts, or visual design.