take fiat currency from config

packages/demobank-ui/src/declaration.d.ts

@@ -364,7 +364,6 @@ namespace SandboxBackend {
       // Contains ratios and fees related to buying
       // and selling the circuit currency.
       ratios_and_fees: RatiosAndFees;
-      currency: string;
     }
     interface RatiosAndFees {
       // Exchange rate to buy the circuit currency from fiat.
@@ -375,6 +374,9 @@ namespace SandboxBackend {
       buy_in_fee: float;
       // Fee to subtract after applying the sell ratio.
       sell_out_fee: float;
+      // Fiat currency.  That is the currency in which
+      // cash-out operations ultimately wire money.
+      fiat_currency: string;
     }
     interface Cashouts {
       // Every string represents a cash-out operation UUID.

packages/demobank-ui/src/hooks/circuit.ts

@@ -288,9 +288,6 @@ export function useRatiosAndFeeConfig(): HttpResponse<
     keepPreviousData: true,
   });
 
-  if (data) {
-    data.data.currency = "FIAT";
-  }
   if (data) return data;
   if (error) return error.info;
   return { loading: true };

packages/demobank-ui/src/pages/BusinessAccount.tsx

@@ -194,6 +194,7 @@ function CreateCashout({
   const sellFee = !config.ratios_and_fees.sell_out_fee
     ? zero
     : Amounts.fromFloat(config.ratios_and_fees.sell_out_fee, balance.currency);
+  const fiatCurrency = config.ratios_and_fees.fiat_currency;
 
   if (!sellRate || sellRate < 0) return <div>error rate</div>;
 
@@ -220,7 +221,7 @@ function CreateCashout({
 
   const __amount_credit = Amounts.sub(credit_before_fee, sellFee).amount;
   const amount_credit = Amounts.parseOrThrow(
-    `${config.currency}:${Amounts.stringifyValue(__amount_credit)}`,
+    `${fiatCurrency}:${Amounts.stringifyValue(__amount_credit)}`,
   );
 
   const balanceAfter = Amounts.sub(balance, amount_debit).amount;
@@ -243,8 +244,6 @@ function CreateCashout({
     channel: !form.channel ? i18n.str`required` : undefined,
   });
 
-  // setErrors(validationResult);
-
   return (
     <div>
       {error && (