Connecting GHE account without Copilot license stops the app from working

I have a Copilot Business plan on my personal GitHub but I'm unable to use the app after connecting to my GHE account which doesn't have a Copilot license: `You are not authorized to use this Copilot feature, it requires an enterprise or organization policy to be enabled.`

Note that this used to work, albeit I was unable to Copilot when starting a session and I'd have to open Copilot CLI using my personal account instead

---
| Field | Value |
| --- | --- |
| App version | 1.1.14 |
| OS | Windows 10.0.26200 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Day 1 |

从 /chat 入口开始，在应用版本 1.1.14 上使用 Copilot Business 的个人账户后，连接一个没有 Copilot 许可证的 GHE 账户，复现该问题。调查授权错误；当连接该 GHE 账户不再导致应用无法使用，同时预期的 Copilot 限制仍然明确时，即可认为问题已完成。

由索引模型根据 Issue 内容生成。