[BUG] opening temporary chat in cc desktop app cleverly switches ur model for more consumption

### Preflight Checklist

- [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) and this hasn't been reported yet
- [x] This is a single bug report (please file separate reports for different bugs)
- [x] I am using the latest version of Claude Code

### What's Wrong?

claude desktop ap 2.110.0 Windows, Electron 44.2.0, Node 24.20.0

when you start a temporary chat your model silently switches to fable always despite what you selected, i know this is an intentional mechanism to silently cost more of the user's quota

### What Should Happen?

it should not automatically swap switch it???

### Error Messages/Logs

```shell
no visible errors
```

### Steps to Reproduce

here's a video - u can clearly see it automatically silently switched to Fable 5.1 despite me selecting Opus or anything else

https://github.com/user-attachments/assets/28bf1445-14ca-4698-b0e8-9858e82ab160

### Claude Model

Not sure / Multiple models

### Is this a regression?

No, this never worked

### Last Working Version

_No response_

### Claude Code Version

2.110.0

### Platform

Other

### Operating System

Windows

### Terminal/Shell

Other

### Additional Information

just see the video its self explanatory

https://github.com/user-attachments/assets/28bf1445-14ca-4698-b0e8-9858e82ab160

No source file or test is named. Reproduce on Windows with Claude desktop app 2.110.0 by selecting Opus or another model, opening a temporary chat, and checking whether it switches to Fable; done means the selected model remains unchanged in the temporary chat.

Written by the indexing model from the issue text.