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.html

@@ -45,7 +45,7 @@
     <div class="data-card">
       <div class="data-row">
         <span class="data-label">VPS</span>
-        <input type="text" id="input-vps-url" class="data-input" placeholder="http://ip:port/management.html#/oauth" />
+        <input type="password" id="input-vps-url" class="data-input" placeholder="http://ip:port/management.html#/oauth" />
       </div>
       <div class="data-row">
         <span class="data-label">Mail</span>