251aa900dd
- Create `tests` directory and `tests/test_feature_engineering.py`. - Add comprehensive pytests covering 10 functions in `features/feature_engineering.py`. - Fix bug in `market_regime_dc` where integer index locations were incorrectly applied to the original DataFrame using `.loc`. - Fix bug in `displacement_detection` where type coercion failed due to combining integer and float series in bitwise AND operations (`&`). - Add assertions for column existence and value range bounding. Co-authored-by: maghdam <63883156+maghdam@users.noreply.github.com>