riskAmt = balance × (risk% ÷ 100)
stopDist = |entry − stopLoss|
── Crypto (fractional units) ──
posSize = riskAmt ÷ stopDist
posValue = posSize × entry
── Contracts (whole numbers) ──
posSize = ⌊ riskAmt ÷ (contractSz × stopDist) ⌋
posValue = contracts × entry × contractSz
── Common ──
leverage = posValue ÷ balance
reward = posSize × |tp − entry| [× contractSz]
R:R = reward ÷ riskAmt
%toSL = (stopDist ÷ entry) × 100
%toTP = (|tp − entry| ÷ entry) × 100