peft tensorboard safetensors mistral alignment-handbook trl sft unsloth generated_from_trainer dataset:HuggingFaceH4/ultrachat_200k base_model:unsloth/mistral-7b-bnb-4bit base_model:adapter:unsloth/mistral-7b-bnb-4bit license:apache-2.0 4-bit bitsandbytes region:us