/** Preserve the existing document_idle initialization and observer behavior. */
function startContentApplication({ environment, page, styles, products }) {
  if (!page.isAllowedPage()) return;
  styles.ensureExtensionStyles();
  products.ensureProductsBackgroundMessageHandler();
  environment.window?.addEventListener?.("hashchange", () => page.insertTile());
  if (page.insertTile()) return;
  const observer = new environment.MutationObserver(() => page.insertTile());
  observer.observe(environment.document.documentElement, { childList: true, subtree: true });
}