backtest.py and multi_timeframe.py read OHLCV CSVs with csv.DictReader
and crashed opaquely on malformed input: a missing column raised a bare
KeyError, a non-numeric cell surfaced NumPy's column-less ValueError,
and an empty or all-NaN series hit IndexError deep in summarize.
Validate the header against the required columns up front, catch
non-numeric cells and report the offending row/column, reject a
header-only file distinctly from a headerless one, and guard resample
and summarize against empty input. Every failure mode now raises a
ValueError naming the file, row and column.
kingchenc
79d705a746