Sub-sessions triggered by a parent session in plan mode no longer respect th...

Sub-sessions triggered by a parent session in plan mode no longer respect the "Plan approval" gate. Instead, agents automatically start implementation.

This seem a natural behaviour for sub-sessions, as they are managed by a parent session. However, it is weird to have the plan mode ask for user confirmation while the session is already working on the implementation.

Idea: Include a flag on which parent sessions can allow plan auto-approve. If "true", sessions started in plan mode are automatically approved (no user prompt) and continue with the recommended implementation mode. If "false", the child session will stop and wait of human review/approval of the plan.

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| Field | Value |
| --- | --- |
| App version | 1.0.26 |
| OS | macOS 26.5.2 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 11 |

该 issue 指出了父会话的计划审批流程和子会话创建路径，但没有给出文件或测试。首先跟踪子会话如何处理计划审批；当一个由父会话控制的设置能够决定子会话计划是自动审批还是等待人工审核，并且两种选择都有覆盖时，即视为完成。

由索引模型根据 Issue 内容生成。