Function cleanup

src/native_pdf_export_patch.ts:178–192

()

	let unloadHandler: (() => void) | null = null;

	const cleanup = () => {
		if (cleanedUp) return;
		cleanedUp = true;
		observer?.disconnect();
		if (intervalId !== null) {
			session.ownerWindow.clearInterval(intervalId);
		}
		if (unloadHandler) {
			popupWindow.removeEventListener("beforeunload", unloadHandler);
			popupWindow.removeEventListener("unload", unloadHandler);
		}
		session.popupCleanups.delete(cleanup);
		session.popupOpened = false;
		maybeCleanupSession(session, "popup closed");
	};

	const scanPopup = () => {
		if (popupWindow.closed) {