0.1.26版本 xAI 的订阅授权不行

### 你想完成什么 / What are you trying to do

0.1.26版本 xAI 的订阅授权不行。Grok Build 的授权码页面成功后，cindy还一直卡着，直到超时结束。

### 已尝试的步骤 / What you have tried

_No response_

### 环境 / Environment

- Cindy 版本或 commit / version or commit:
- 平台与版本 / platform & OS version:

Start by reproducing xAI subscription authorization in Cindy 0.1.26 and record the platform and OS version. Check the flow after the Grok Build authorization page reports success, with completion defined as Cindy receiving the authorization before the timeout.

Written by the indexing model from the issue text.