The Pydantic model sets volume=None when absent, creating an all-NaN
column rather than a missing column. Check isna().all() in addition
to column existence.
- Fill volume with 0 when column is absent from candle data
- Skip MFI/OBV/AD/ADOSC indicators when no real volume data available
- Fix pandas FutureWarning for inplace fillna in candle_features
- Remove temporary debug NaN logging