When using Devin on Github PRs I keep forgetting to prefix my comments with "aside -" which causes accidental changes. Vibe coded some a quick user script after a lot of iterations to add it by default

github-devin-aside.js

// ==UserScript==
// @name         GitHub Comment "aside -" Prefix
// @namespace    http://tampermonkey.net/
// @version      28.0
// @description  Auto-prefixes GitHub PR comments with "aside -" for Devin
// @match        https://github.com/*
// @grant        none
// ==/UserScript==

(function () {
  'use strict';

  const PREFIX = 'aside - ';
  const DEBUG = true;
  const log = (...args) => DEBUG && console.log('[aside]', ...args);

  function insertPrefix(ta) {
    if (ta.value.startsWith(PREFIX)) return;
    ta.focus();
    document.execCommand('insertText', false, PREFIX);
    log('inserted prefix into', ta.id || ta.className);
  }

  function prefixTextarea(ta) {
    if (ta.dataset.asidePrefixed) return;
    ta.dataset.asidePrefixed = 'true';
    log('attaching to', ta.id || ta.className);

    ta.addEventListener('focus', () => insertPrefix(ta));
    ta.addEventListener('input', () => {
      if (!ta.value.startsWith(PREFIX)) {
        const pos = ta.selectionStart;
        const cur = ta.value;
        ta.value = cur.length < PREFIX.length ? PREFIX : PREFIX + cur.replace(/^(aside - ?)?/, '');
        ta.dispatchEvent(new Event('input', { bubbles: true }));
        ta.setSelectionRange(Math.max(PREFIX.length, pos), Math.max(PREFIX.length, pos));
      }
    });
  }

  const observer = new MutationObserver(() =>
    document.querySelectorAll(
      'textarea.js-comment-field, textarea[name="comment[body]"], textarea[name="pull_request_review[body]"], textarea.prc-Textarea-TextArea-snlco'
    ).forEach(prefixTextarea)
  );

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

sometimes it doesn't work, but a page refresh seems to fix it. not sure what's up