- Add model registry system for dynamic model loading
- Implement LlamaForCausalLM with Llama3 RoPE scaling
- Register Qwen3ForCausalLM and Qwen2ForCausalLM
- Update ModelRunner to use get_model_class() for dynamic model selection
Tested: needle 32k test PASSED
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>