[Bug] Image clipboard detection fails despite valid image present

**Bug Description**
image not found on clipboard, but i have it and it work out claude

**Environment Info**
- Platform: linux
- Terminal: ghostty
- Version: 2.1.274
- Feedback ID: 6e1c676e-961a-45b9-baea-fcb154d4d710

**Errors**
```json
[]
```

Start by reproducing the clipboard image detection failure on Linux while running in Ghostty, using a clipboard that contains a valid image. Trace the clipboard detection entry point and compare its behavior with the reported successful case; done means the image is detected reliably and the relevant regression or behavior is covered by a test.

Written by the indexing model from the issue text.