// Boot overlay is now owned entirely by site/boot-preload.js (a plain script
// that runs before Babel, paints the loading screen instantly, animates it,
// and lazily loads the rest of the app behind it). BootIntro stays in the
// component tree as an inert placeholder so every page's JSX keeps compiling
// unchanged — it renders nothing and touches no state.
function BootIntro() {
  return null;
}