chore: pre-release cleanup

- Remove dead chatgpt.js (unused — all auth flows go through signup-page.js)
- Remove chatgpt.com from manifest content_scripts
- Fix resetState() to preserve vpsUrl and mailProvider on manual reset
- Add 30s timeout to all tabs.onUpdated listeners (prevent hanging)
- Fix misleading "All runs finished" log when loop breaks early
- Remove stale TODO comment in signup-page.js
- Add disabled styles for .btn-primary and .run-count-input
- Remove unused `indicator` variable in sidepanel.js
- Fix trailing comma in manifest.json

sidepanel/sidepanel.js

@@ -107,7 +107,6 @@ async function restoreState() {
 function updateStepUI(step, status) {
   const statusEl = document.querySelector(`.step-status[data-step="${step}"]`);
   const row = document.querySelector(`.step-row[data-step="${step}"]`);
-  const indicator = document.querySelector(`.step-indicator[data-step="${step}"]`);
 
   if (statusEl) statusEl.textContent = STATUS_ICONS[status] || '';
   if (row) {