[BUG] Remove think tags for the reasoning model output

### What version of eigent are you using?

0.0.82

### System information

N/A

### Problem description

Extra think tags for reasoning model output
<img width="425" height="809" alt="Image" src="https://github.com/user-attachments/assets/cadb3750-c305-486c-b080-ae24352a5b3d" />

### log

N/A

### Additional context

_No response_