=== Task 4: multi-instrument comparison (same breakout, GER40 vs FRA40) ===

symbol   pip-meaning    sessions total_pips     max_dd   flips
--------------------------------------------------------------
GER40    index point          62      203.4      168.5     124
FRA40    index point          63       83.7       62.7     126

Honesty of the cross-asset comparison:
  Both GER40 and FRA40 are index points (pip=1.0), so their pip totals
  ARE directly comparable here — BUT only because the researcher knew
  to pass pip=1.0 for both. The engine has NO instrument registry: pip
  is a bare f64 to SimBroker::new, and nothing would stop (or flag) a
  comparison of GER40 index-pips to EURUSD fx-pips with mismatched scale.
