Why can't we rename the session from the agent more than once?

Why can't we rename the session from the agent more than once? I want to have the agent update the session display name so I can keep track of status, what I'm working on in that session, etc.

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| Field | Value |
| --- | --- |
| App version | 1.0.19 |
| OS | Windows 10.0.26200 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 3 |

首先，在报告的应用版本中复现 /chat 体验里的重命名行为，并观察 agent 第二次更新会话显示名称时会发生什么。跟踪会话命名入口和现有的重命名处理，然后验证 agent 驱动的重复更新会更改显示名称，且不会破坏会话。

由索引模型根据 Issue 内容生成。