frontend-data-bm25-engine-zero-external-dependencies

The BM25 search engine in frontend-data (core.py, search.py, design_system.py) uses pure Python with no pip dependencies — it reads CSV files directly from the skill’s data/ directory. This means no Docker container, no venv, no requirements.txt needed. The engine resolves DATA_DIR via Path(__file__).parent.parent / 'data' relative to script location.