[Model Request] Add support for Cartik/Sonexa-1-Chat #3901

Hello LMSYS and Arena team,

I would like to request adding our new open-source coding model to the Chatbot Arena leaderboard for evaluation. It is fully open and hosted on Hugging Face.

Model Details:

• Model Name: Sonexa-1-Chat
• Hugging Face Link: https://huggingface.co/Cartik/Sonexa-1-Chat
• Base Architecture: Qwen3
• Model Size: 4B parameters
• Primary Focus: Code generation and technical instruction following

Configuration & Templates:

• Chat Template: Standard Qwen3 / ChatML format (the model correctly utilizes <|im_start|> and <|im_end|> tokens).
• Tokenizer: Uses the default Qwen3Tokenizer setup.

The model has been tested and shows stable performance on standard programming tasks, outputting clean Markdown and syntactically correct code blocks. We would love to see how it performs in the blind testing environment against other models in its weight class.

Please let me know if you need any additional configurations, API endpoints, or if I should prepare a Pull Request for fastchat/conversation.py to ensure the template renders perfectly.

Thank you for your amazing work on the Arena!

Best regards,
Cartik