Port Tier 1 hobbyist to Llama-3.2-3B

[caiovicentino]

Copy 01_hobbyist_gemma2_2b_colab.ipynb, swap MODEL_ID + D_MODEL + LAYER for Llama-3.2-3B. Validate on Colab Free T4, report final var_exp. New file: 24_hobbyist_llama32_3b_colab.ipynb.