[Feature] Could you support this gemini API format?

I want to support
```
/v1beta/models/gemini-2.5-pro:generateContent
```
<img width="1150" height="178" alt="Image" src="https://github.com/user-attachments/assets/f13d6d4a-a874-4cb6-8b6b-a39f6c71cd9c" />

But generic-chat-completion-api only support this?
<img width="656" height="130" alt="Image" src="https://github.com/user-attachments/assets/394725dc-de70-42d0-840b-1ccccd8d2c3e" />