removed legacy from bff

frontend/pshared/lib/utils/payment/quote_helpers.dart

@@ -0,0 +1,92 @@
+import 'package:pshared/models/money.dart';
+import 'package:pshared/models/payment/fees/line.dart';
+import 'package:pshared/models/payment/quote/quote.dart';
+import 'package:pshared/utils/currency.dart';
+import 'package:pshared/utils/money.dart';
+
+Money? quoteFeeTotal(PaymentQuote? quote) {
+  final preferredCurrency =
+      quote?.amounts?.sourcePrincipal?.currency ??
+      quote?.amounts?.sourceDebitTotal?.currency;
+  return quoteFeeTotalFromLines(
+    quote?.fees?.lines,
+    preferredCurrency: preferredCurrency,
+  );
+}
+
+Money? quoteFeeTotalFromLines(
+  List<FeeLine>? lines, {
+  String? preferredCurrency,
+}) {
+  if (lines == null || lines.isEmpty) return null;
+
+  final normalizedPreferred = _normalizeCurrency(preferredCurrency);
+  final totalsByCurrency = <String, double>{};
+
+  for (final line in lines) {
+    final money = line.amount;
+    if (money == null) continue;
+
+    final currency = _normalizeCurrency(money.currency);
+    if (currency == null) continue;
+
+    final amount = parseMoneyAmount(money.amount, fallback: double.nan);
+    if (amount.isNaN) continue;
+
+    final sign = _lineSign(line.side);
+    final signedAmount = sign * amount.abs();
+    totalsByCurrency[currency] =
+        (totalsByCurrency[currency] ?? 0) + signedAmount;
+  }
+
+  if (totalsByCurrency.isEmpty) return null;
+
+  final selectedCurrency =
+      normalizedPreferred != null &&
+          totalsByCurrency.containsKey(normalizedPreferred)
+      ? normalizedPreferred
+      : totalsByCurrency.keys.first;
+  final total = totalsByCurrency[selectedCurrency];
+  if (total == null) return null;
+
+  return Money(amount: amountToString(total), currency: selectedCurrency);
+}
+
+List<Money> aggregateMoneyByCurrency(Iterable<Money?> values) {
+  final totals = <String, double>{};
+  for (final value in values) {
+    if (value == null) continue;
+
+    final currency = _normalizeCurrency(value.currency);
+    if (currency == null) continue;
+
+    final amount = parseMoneyAmount(value.amount, fallback: double.nan);
+    if (amount.isNaN) continue;
+
+    totals[currency] = (totals[currency] ?? 0) + amount;
+  }
+
+  return totals.entries
+      .map(
+        (entry) =>
+            Money(amount: amountToString(entry.value), currency: entry.key),
+      )
+      .toList();
+}
+
+double _lineSign(String? side) {
+  final normalized = side?.trim().toLowerCase() ?? '';
+  switch (normalized) {
+    case 'entry_side_credit':
+    case 'credit':
+      return -1;
+    default:
+      return 1;
+  }
+}
+
+String? _normalizeCurrency(String? currency) {
+  final normalized = currency?.trim().toUpperCase();
+  if (normalized == null || normalized.isEmpty) return null;
+  return normalized;
+}