fix: count brokerage cash once and skip short-position return percent (WealthLedger/backend#140)

src/modules/investments/portfolio/infrastructure/tbank-portfolio.mapper.ts

@@ -126,7 +126,8 @@ function totalsByCurrency(
   for (const value of money) addTotal(value.currency, decimal(value));
   for (const position of positions) {
     const price = position.currentPrice;
-    if (!price) continue;
+    // CURRENCY positions mirror the cash balances already added above.
+    if (!price || types[position.instrumentType?.toLowerCase() ?? ''] === 'CURRENCY') continue;
     addTotal(
       price.currency,
       multiply(decimal(position.quantity ?? {}), decimal(price)),