Branch: work-from-91d0cf0
Adds scripts/auto_tune.py (with hardcoded / llm / llm-explore modes, --model flag, merge-and-test step, --events stream), ui/auto_tune_ui.py (Streamlit frontend), and the /auto-tune FastAPI endpoint for the UI to call against a remote MI300X server. The Space's app_file now points at the auto-tune UI.
Upload tests/fixtures/cached_audit.json with huggingface_hub
