fix: set HF_HUB_OFFLINE=1 at runtime to prevent model network calls on startup

feat: multi-key rotation for Gemini (3 keys) and Groq (3 keys)

feat: full optimization - Groq LLM, disease cache, deploy configs

Push all code to huy_xau_trai repository

Add RAG integration: Flask API server, disease selector, evaluation system with improved case generation