[Model Request] Gemma 4

I would like to propose adding support for Gemma 4 as a built-in model in WebLLM.

Available Models

Model	Total Params	Active Params	Architecture
Gemma 4 31B	30.7B	30.7B	Dense
Gemma 4 26B A4B	25.2B	3.8B	MoE( 128 experts, 8 active and 1 shared)
Gemma 4 E4B	4.5B effective (8B with embeddings)		Dense
Gemma 4 E2B	2.3B effective (5.1B with embeddings)		Dense

Why Gemma 4 for WebLLM?

• Native Multimodal Support (Vision/Audio)
• Superior Efficiency-to-Performance Ratio: Gemma 4 achieves state-of-the-art results while maintaining a smaller parameter count than competitors. This makes it stable for VRAM-constrained environments like Chrome/Edge.
• Apache 2.0 Licensing: The Apache 2.0 license removes commercial barriers. This will likely bring more web developers to the ecosystem.
• Optimized for Agentic Workflows: Gemma 4 is fine-tuned for "Chain of Thought" reasoning and tool-calling.

Weights are available on Hugging Face.