Add SFT training script for Phase 3 (cybersecurity instruction fine-tuning)

Add comprehensive eval script (standard LM + security benchmarks + depth extrapolation)

Add Phase 3 SFT training script for Ultron-Sec

Upload train_cpt.py

Update train_ultron.py

Update benchmark_ultron.py

Add train_ultron.py

Add notebooks/ultron_notebook.ipynb

Add tests/test_ultron.py

Add ultron/train.py

Add ultron/variants.py

Add ultron/model.py

Add ultron package init

Add Ultron README

initial commit