fix: bug

app/templates/billing.html

@@ -31,6 +31,7 @@
       <div class="workspace">
         <header class="topbar topbar-compact">
           <div class="topbar-actions">
+            <span class="mode-badge global-mode-hint">当前模型模式：自由模型</span>
             <a class="icon-btn" href="/" aria-label="返回工作台" title="返回工作台">⌂</a>
             <a class="icon-btn" href="/settings" aria-label="账号与模型设置" title="账号与模型设置">⚙</a>
             <a class="icon-btn" href="/upgrade" aria-label="升级" title="升级">★</a>
@@ -95,6 +96,7 @@
       </div>
     </div>
     <script src="/static/ui-dialog.js?v=20260428a"></script>
+    <script src="/static/mode-hint.js?v=20260428a"></script>
     <script src="/static/billing.js?v=20260428w"></script>
   </body>
 </html>