- 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>