Copilot doesn't work well after manually edit code.

**Describe the bug**

Copilot always revert my edited code to previous code.

**Versions**
- Copilot for Xcode: 0.43.140
- Xcode: 26.0.1
- macOS: 26.0.1

**Steps to reproduce**
1. Ask Copilot to change some code.
2. Manually change some code.
3. Ask Copilot to change some other code.

Copilot will do the task I ask, but always revert what I changed. Create new tab will be the same. Only quit and reopen will work.

It reason is because copilot always read it cache instead of the file in Xcode. Copilot knows it and it doesn't follow my instruction to read from Xcode. It answers but still using the cache.

**Screenshots**

**Logs**

**Additional context**