Create a notification when model is stopping due to content filtering

Create a notification when model is stopping due to content filtering

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| Field | Value |
| --- | --- |
| App version | 1.0.23 |
| OS | Windows 10.0.26220 |
| Theme | Notionish |
| Path | /chat |
| Tenure | Week 9 |

从 /chat 流程开始，追踪模型停止和内容过滤的处理位置。确定现有的通知或消息展示路径，然后将完成标准定义为：当内容过滤使模型停止时显示一条清晰的通知；issue 未指定文件或测试，因此请与 maintainer 确认预期的措辞和 UI。

由索引模型根据 Issue 内容生成。