Adds the gm-shell root element that owns store/clock/stamps/scenario,
mounts director-rail and dice-tray, handles reached (stamp + persist)
and open-tool (toggle dice tray), and boots the AFTERIMAGE scenario in
main.js. Also adds tests/setup.js + a vite.config.js setupFiles entry:
Node's newer built-in global `localStorage` shadows jsdom's per-window
implementation in vitest's jsdom environment, leaving localStorage
undefined in tests until replaced with a real jsdom-backed instance.
tevans