Qwen Chat: chime when generation finishes

Beep when Qwen finishes, even if you're on another tab.
换行
// ==UserScript==
// @name        Qwen Chat: chime when generation finishes
// @name:ru     Qwen Chat: звуковой сигнал по завершении генерации
// @version     1.0
// @description Beep when Qwen finishes, even if you're on another tab.
// @description:ru Издает звуковой сигнал, когда Qwen заканчивает генерацию, даже если вы находитесь на другой вкладке.
// @author      a114_you
// @match       https://chat.qwen.ai/*
// @grant       none
// @run-at      document-end
// @license MIT
// @namespace https://greasyfork.org/users/1475624
// ==/UserScript==

(() => {
    let generating = false, ctx;
    const unlock = () => (ctx = new (window.AudioContext || window.webkitAudioContext)());
    document.documentElement.onclick = unlock;

    const play = () => {
        const c = ctx || unlock();
        if (c.state === 'suspended') c.resume();

        const g = c.createGain();
        g.gain.value = 0.3;
        g.connect(c.destination);

        let t = c.currentTime;
        [440,660,880].forEach((f,i) => {
            const o = c.createOscillator();
            o.frequency.value = f;
            o.connect(g);
            o.start(t);
            o.stop(t += [0.2,0.2,0.3][i]);
        });

        setTimeout(g.disconnect.bind(g), 800);
    };

    const isGenerating = () =>
        !!document.querySelector('i.icon-StopIcon') &&
        !document.querySelector('i.icon-line-arrow-up');

    const check = () => {
        const now = isGenerating();
        if (generating !== now) {
            generating = now;
            !now && play();
        }
    };

    new MutationObserver(check).observe(document.body, {
        childList: true,
        subtree: true,
        attributes: true
    });

    document.readyState === 'complete' ? check() : window.onload = check;
})();