Add Evans decision tree analysis pipeline (Steps 3–7)

Merge GitHub initial commit — keep project README

Add multi-provider model selection, decision tree simulation engine, and formatter

Initial commit

Fix pydantic pin to 2.12.5 — HuggingFace gradio[mcp] requires <=2.12.5

Merge HuggingFace default gitattributes with project LFS config

Initial deployment: pubHealthLLM public health decision intelligence app

initial commit