Updated playground model list

This release updates the playground model list to the latest available offerings.

Features

• Updated playground models #2101  - Updated the playground model list to add Claude Sonnet 4.6, GPT-5.4 Mini, o4-mini, o3, Gemini 3.1 Pro, DeepSeek R1/V3.2, Llama 4 Maverick, Grok 4, and Qwen3 Coder, and removed superseded models. (Author: @simplesagar )