[Bugs] How do I refresh a project?

**Mood:** 😔
**Category:** Bugs

How do I refresh a project? When I create a new session, I want to eithe rhave a button to resync (Refresh) cause I always tell the agent to "fetch origin/main and reset this new worktree with origin/main" I think deterministic resync is better than wasting tokens.

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| Field | Value |
| --- | --- |
| App version | 1.0.15 |
| OS | Windows 10.0.26200 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 6 |

从 /chat 项目和 new-session 流程开始，重点关注新 worktree 的初始化方式。围绕所请求的 fetch-and-resync 行为定义 refresh 操作，然后验证按钮是否能可靠地将新会话带回 origin/main。

由索引模型根据 Issue 内容生成。