Setup Design Infra

The contract is a set of named design decisions (tokens plus component names), and designs, apps and every framework rendering of them speak only in those names. Phase A installs the structure; phase B settles the values in it. prototype-to-design reconciles a screen against those values and never designs a scale. Every path, glob and command installed must resolve to something real in this repo.

Everything installed here is durable, and that is what separates it from the designs it serves: a design is a ticket plus a branch that both go when its screen ships, while the kit below outlives every screen. Nothing here is written per screen.

A1. Detect the target stack

Look before asking (tailwindcss in the manifest? react-native / tamagui? a Package.swift with a UI module? both?), confirm with the user, then pick the shape: