multi-exit algo trades now count as one trade in optimizer and analyzer

the optimizer and algo analyzer now count a position closed in two or more partial exits as one trade. before, each exit counted separately, which skewed win rate, average P&L, and how strategies ranked against each other.

all exits tied to the same entry are now grouped into one position. two $1,500 stop-outs on one entry show as a single $3,000 losing trade, not two smaller ones.

optimizer rankings, holdout scoring, Monte Carlo simulations, and prop firm drawdown checks all use the grouped positions. the trades tab still lists each individual exit, numbered by position, so every fill stays visible.