Fix single-row prediction error and enable high-speed HF transfers

Move Dockerfile to root for Hugging Face detection

formatted

Revert back

fix: pre-download SAP model weights and unify HF login

feat: finalized stable architecture with consolidated structure and single-worker mode

fix: revert to tabpfn v2, add TABPFN_TOKEN support, and update v2 API usage

fix: pre-accept TabPFN license in Dockerfile ENV + cache file + all env var names

Initial deployment of ModelMatrix-HF