Prove the render path end-to-end: bring up UIKit + Metal (already
scaffolded), clear to a solid blue, and draw one centered orange quad via
the GPU protocol's clear+quad path — an MSL pass-through pipeline plus a
6-vertex (2-triangle) NDC buffer, created lazily once the MTLDevice exists.
Geometry is NDC [-0.5, 0.5]² so the quad is the central 50%x50% of the
drawable regardless of device resolution, keeping the screenshot golden
unambiguous. Background (0.10, 0.20, 0.55), quad (1.0, 0.6, 0.0).
goldens/p0_quad.png is the first screenshot golden, captured from the
booted iOS 26.0 simulator after install + launch.
Stand up build.sx (macos + ios/ios-sim targets, bundle id
co.swipelab.m3te, output sx-out/ios/M3te.app, assets dir) and a minimal
main.sx that brings up the platform (UIKit+Metal on iOS, SDL3+GL on
macOS) and renders a solid-clear frame. Add assets/ and goldens/
directories and a .gitignore for build artifacts.
Modeled on game/build.sx and game/main.sx; modules resolve from the
compiler binary with no -L flag.
