Fix: keep Colab defaults, install only trl+peft with --no-deps, handle all TRL versions

Fix: let pip resolve all versions, uninstall old transformers, auto-restart if needed

Fix: uninstall old transformers first, pin exact versions, restart runtime

Fix: reinstall torchvision first, pin transformers 4.47-4.49, no runtime restart

Fix: use Colab default torch, auto-detect TRL API, no version pins

Fix: keep Colab default torch, only install sympy fix + training libs

Fix: restart runtime after pip install to resolve sympy/torch conflict

Fix: pin sympy + all deps to avoid Colab version conflicts

Add training notebook (runnable on Colab/HF)