waitForReactSelectMenu function infrastructure ~ 75.0%

function waitForReactSelectMenu(
  wrapper: HTMLElement,
  timeoutMs: number,
): Promise<HTMLElement | null> {
  const findInline = () =>
    wrapper.querySelector<HTMLElement>(".react-select__menu");

  // Re-read aria-controls on every check because react-select only sets it
  // while the menu is open (aria-expanded="true").
  const findPortaled = (): HTMLElement | null => {
    const input = wrapper.querySelector<HTMLInputElement>(
      "input[aria-controls]",
    );
    const listboxId = input?.getAttribute("aria-controls") ?? null;
    if (listboxId) {
      const listbox = document.getElementById(listboxId);
      const byAriaControls =
        listbox?.closest<HTMLElement>(".react-select__menu") ?? null;
      if (byAriaControls) return byAriaControls;
    }

    // Broader fallback: any .react-select__menu in the document that is NOT
    // a child of this wrapper (i.e. a portaled one).
    const allMenus = Array.from(
      document.querySelectorAll<HTMLElement>(".react-select__menu"),
    );
    return allMenus.find((m) => !wrapper.contains(m)) ?? null;
  };

  const existing = findInline() ?? findPortaled();
  if (existing) return Promise.resolve(existing);

  return new Promise((resolve) => {
    const observer = new MutationObserver(() => {
      const found = findInline() ?? findPortaled();
      if (found) {
        observer.disconnect();
        resolve(found);
      }
    });

    observer.observe(document.body, { childList: true, subtree: true });

    setTimeout(() => {
      observer.disconnect();
      resolve(findInline() ?? findPortaled());
    }, timeoutMs);
  });
}