Created nested session doesn't have access to skills that the parent session ...

Created nested session doesn't have access to skills that the parent session had access to.

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| Field | Value |
| --- | --- |
| App version | 1.0.25 |
| OS | macOS 26.2.0 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 10 |

从 /chat 流程开始，复现所描述的嵌套会话问题，并将其可用的 skills 与父会话的 skills 进行比较。完成标准是嵌套会话能够访问其父会话可用的 skills；payload 未指明源文件或测试，因此首先定位相关的会话和 skill 处理入口点。

由索引模型根据 Issue 内容生成。