yfinance 1.4.0 regressed the daily-download index to unnamed, so
reset_index() produced an "index" column instead of "Date" and every
stockstats indicator silently failed (no SMA/RSI/MACD/Bollinger/ATR).
Verified across versions: 1.2.0 / 1.3.0 / 1.4.1 name it "Date"; only
1.4.0 is broken. Pin to >=1.4.1 (the upstream fix) and normalize the
date column defensively so a non-"Date" index can't silently drop
indicators on any build.
#890
