pub fn settle_batch(
inputs: &[SettlementInput],
) -> (Vec<SettlementOutput>, Decimal)Expand description
Settle a batch of positions and return per-position outputs plus total PnL.
If the input positions net to zero (sum of position_size = 0, same strike/expiry/entry),
then total_pnl will be zero. This is the zero-sum invariant.