feat(frontend): add i18n support for Fiat Onramp Integration Interface

Replaces the hardcoded English copy added for the SEP-24 deposit modal
(title, form labels, per-step loading messages, error fallback, iframe
title) with next-intl translations under a new "fiatOnramp" namespace,
translated for all three supported locales (en, es, pt). The dashboard's
"Buy / Deposit" trigger button is localized too since it's part of the
same feature surface.

Closes #1212

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: Abidoyesimze

frontend/messages/en.json

@@ -452,5 +452,25 @@
     "dismissLabel": "Dismiss notification: {message}",
     "notificationLabel": "Notification: {message}",
     "timestampLabel": "Timestamp: {timestamp}"
+  },
+  "fiatOnramp": {
+    "title": "Buy / Deposit Funds",
+    "triggerLabel": "Buy / Deposit",
+    "description": "Deposit fiat via a Stellar anchor (SEP-0024). Funds arrive as tokens directly in your connected wallet.",
+    "selectAsset": "Select Asset",
+    "amountLabel": "Amount",
+    "amountOptional": "(optional)",
+    "amountPlaceholder": "e.g. {amount} {asset}",
+    "anchorDomainLabel": "Anchor Domain",
+    "anchorDomainPlaceholder": "e.g. testanchor.stellar.org",
+    "continueButton": "Continue to Anchor",
+    "footerNote": "Secured by Stellar Network - SEP-0024 Standard",
+    "stepConnecting": "Connecting to anchor...",
+    "stepAuth": "Waiting for wallet signature...",
+    "stepGenerating": "Preparing your deposit form...",
+    "authHint": "Please sign the challenge transaction in your wallet to securely connect to {domain}.",
+    "genericHint": "This should only take a moment.",
+    "iframeTitle": "Anchor deposit form",
+    "genericError": "Deposit failed"
   }
-}
+}

frontend/messages/es.json

@@ -452,5 +452,25 @@
     "dismissLabel": "Descartar notificación: {message}",
     "notificationLabel": "Notificación: {message}",
     "timestampLabel": "Marca de tiempo: {timestamp}"
+  },
+  "fiatOnramp": {
+    "title": "Comprar / Depositar Fondos",
+    "triggerLabel": "Comprar / Depositar",
+    "description": "Deposita fiat a traves de un anchor de Stellar (SEP-0024). Los fondos llegan como tokens directamente a tu billetera conectada.",
+    "selectAsset": "Seleccionar Activo",
+    "amountLabel": "Monto",
+    "amountOptional": "(opcional)",
+    "amountPlaceholder": "ej. {amount} {asset}",
+    "anchorDomainLabel": "Dominio del Anchor",
+    "anchorDomainPlaceholder": "ej. testanchor.stellar.org",
+    "continueButton": "Continuar al Anchor",
+    "footerNote": "Protegido por la red Stellar - Estandar SEP-0024",
+    "stepConnecting": "Conectando con el anchor...",
+    "stepAuth": "Esperando firma de la billetera...",
+    "stepGenerating": "Preparando tu formulario de deposito...",
+    "authHint": "Firma la transaccion de desafio en tu billetera para conectarte de forma segura a {domain}.",
+    "genericHint": "Esto solo deberia tomar un momento.",
+    "iframeTitle": "Formulario de deposito del anchor",
+    "genericError": "El deposito fallo"
   }
 }

frontend/messages/pt.json

@@ -452,5 +452,25 @@
     "dismissLabel": "Dispensar notificacao: {message}",
     "notificationLabel": "Notificacao: {message}",
     "timestampLabel": "Carimbo de data/hora: {timestamp}"
+  },
+  "fiatOnramp": {
+    "title": "Comprar / Depositar Fundos",
+    "triggerLabel": "Comprar / Depositar",
+    "description": "Deposite fiat atraves de um anchor Stellar (SEP-0024). Os fundos chegam como tokens diretamente na sua carteira conectada.",
+    "selectAsset": "Selecionar Ativo",
+    "amountLabel": "Valor",
+    "amountOptional": "(opcional)",
+    "amountPlaceholder": "ex. {amount} {asset}",
+    "anchorDomainLabel": "Dominio do Anchor",
+    "anchorDomainPlaceholder": "ex. testanchor.stellar.org",
+    "continueButton": "Continuar para o Anchor",
+    "footerNote": "Protegido pela rede Stellar - Padrao SEP-0024",
+    "stepConnecting": "Conectando ao anchor...",
+    "stepAuth": "Aguardando assinatura da carteira...",
+    "stepGenerating": "Preparando seu formulario de deposito...",
+    "authHint": "Assine a transacao de desafio na sua carteira para se conectar com seguranca a {domain}.",
+    "genericHint": "Isso deve levar apenas um momento.",
+    "iframeTitle": "Formulario de deposito do anchor",
+    "genericError": "Falha no deposito"
   }
 }

frontend/src/app/(authenticated)/dashboard/page.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import React, { useState, useEffect } from "react";
+import { useTranslations } from "next-intl";
 import DashboardSkeleton from "@/components/DashboardSkeleton";
 import Link from "next/link";
 import {
@@ -15,6 +16,7 @@ import PaymentsTabs from "@/components/PaymentsTabs";
 import FiatOnrampModal from "@/components/FiatOnrampModal";
 
 export default function DashboardPage() {
+  const t = useTranslations("fiatOnramp");
   const [isFirstKeyModalOpen, setIsFirstKeyModalOpen] = useState(false);
   const [isOnrampModalOpen, setIsOnrampModalOpen] = useState(false);
   const hydrated = useMerchantHydrated();
@@ -91,7 +93,7 @@ export default function DashboardPage() {
                 d="M12 9v3m0 0v3m0-3h3m-3 0H9m12 0a9 9 0 11-18 0 9 9 0 0118 0z"
               />
             </svg>
-            Buy / Deposit
+            {t("triggerLabel")}
           </button>
 
           <Link

frontend/src/components/FiatOnrampModal.test.tsx

@@ -2,9 +2,42 @@ import React from "react";
 import { describe, it, expect, vi, beforeEach } from "vitest";
 import { render, screen, fireEvent, waitFor } from "@testing-library/react";
 import "@testing-library/jest-dom/vitest";
+import { NextIntlClientProvider } from "next-intl";
 
 import FiatOnrampModal from "./FiatOnrampModal";
 
+const messages = {
+  fiatOnramp: {
+    title: "Buy / Deposit Funds",
+    triggerLabel: "Buy / Deposit",
+    description:
+      "Deposit fiat via a Stellar anchor (SEP-0024). Funds arrive as tokens directly in your connected wallet.",
+    selectAsset: "Select Asset",
+    amountLabel: "Amount",
+    amountOptional: "(optional)",
+    amountPlaceholder: "e.g. {amount} {asset}",
+    anchorDomainLabel: "Anchor Domain",
+    anchorDomainPlaceholder: "e.g. testanchor.stellar.org",
+    continueButton: "Continue to Anchor",
+    footerNote: "Secured by Stellar Network - SEP-0024 Standard",
+    stepConnecting: "Connecting to anchor...",
+    stepAuth: "Waiting for wallet signature...",
+    stepGenerating: "Preparing your deposit form...",
+    authHint: "Please sign the challenge transaction in your wallet to securely connect to {domain}.",
+    genericHint: "This should only take a moment.",
+    iframeTitle: "Anchor deposit form",
+    genericError: "Deposit failed",
+  },
+};
+
+function renderModal(props: { isOpen: boolean; onClose: () => void }) {
+  return render(
+    <NextIntlClientProvider locale="en" messages={messages}>
+      <FiatOnrampModal {...props} />
+    </NextIntlClientProvider>,
+  );
+}
+
 // ─── framer-motion mock ───────────────────────────────────────────────────────
 // jsdom has no layout engine so framer-motion's measurement APIs fail; strip
 // animation-only props and render plain HTML so the DOM stays inspectable.
@@ -56,20 +89,20 @@ describe("FiatOnrampModal", () => {
   });
 
   it("does not render when closed", () => {
-    render(<FiatOnrampModal isOpen={false} onClose={vi.fn()} />);
+    renderModal({ isOpen: false, onClose: vi.fn() });
     expect(screen.queryByText("Buy / Deposit Funds")).not.toBeInTheDocument();
   });
 
   it("renders the asset selection form when open", () => {
-    render(<FiatOnrampModal isOpen onClose={vi.fn()} />);
+    renderModal({ isOpen: true, onClose: vi.fn() });
     expect(screen.getByText("Buy / Deposit Funds")).toBeInTheDocument();
     expect(screen.getByRole("button", { name: /USDC/ })).toBeInTheDocument();
     expect(screen.getByRole("button", { name: /SRT/ })).toBeInTheDocument();
     expect(screen.getByRole("button", { name: "Continue to Anchor" })).toBeInTheDocument();
   });
 
   it("lets the user switch the selected asset", () => {
-    render(<FiatOnrampModal isOpen onClose={vi.fn()} />);
+    renderModal({ isOpen: true, onClose: vi.fn() });
     const usdcButton = screen.getByRole("button", { name: /USDC/ });
     const srtButton = screen.getByRole("button", { name: /SRT/ });
 
@@ -83,7 +116,7 @@ describe("FiatOnrampModal", () => {
   });
 
   it("walks through connecting, auth, and generating loading states before showing the interactive iframe", async () => {
-    render(<FiatOnrampModal isOpen onClose={vi.fn()} />);
+    renderModal({ isOpen: true, onClose: vi.fn() });
 
     fireEvent.click(screen.getByRole("button", { name: "Continue to Anchor" }));
 
@@ -112,7 +145,7 @@ describe("FiatOnrampModal", () => {
   });
 
   it("passes the entered amount through to initiateDeposit", async () => {
-    render(<FiatOnrampModal isOpen onClose={vi.fn()} />);
+    renderModal({ isOpen: true, onClose: vi.fn() });
 
     fireEvent.change(screen.getByLabelText(/Amount/), { target: { value: "250" } });
     fireEvent.click(screen.getByRole("button", { name: "Continue to Anchor" }));
@@ -131,7 +164,7 @@ describe("FiatOnrampModal", () => {
   it("shows an inline error and returns to the select step when the wallet is unavailable", async () => {
     mockGetFreighterPublicKey.mockRejectedValue(new Error("Freighter is not installed"));
 
-    render(<FiatOnrampModal isOpen onClose={vi.fn()} />);
+    renderModal({ isOpen: true, onClose: vi.fn() });
     fireEvent.click(screen.getByRole("button", { name: "Continue to Anchor" }));
 
     await waitFor(() => {
@@ -144,7 +177,7 @@ describe("FiatOnrampModal", () => {
 
   it("resets state and calls onClose when closed", () => {
     const onClose = vi.fn();
-    render(<FiatOnrampModal isOpen onClose={onClose} />);
+    renderModal({ isOpen: true, onClose });
 
     fireEvent.click(screen.getByTestId("modal-close"));
 

frontend/src/components/FiatOnrampModal.tsx

@@ -2,6 +2,7 @@
 
 import { useCallback, useState } from "react";
 import { AnimatePresence, motion } from "framer-motion";
+import { useTranslations } from "next-intl";
 import Skeleton from "react-loading-skeleton";
 import "react-loading-skeleton/dist/skeleton.css";
 import {
@@ -33,14 +34,16 @@ const SUPPORTED_ASSETS = [
 ];
 
 type Step = "SELECT" | "CONNECTING" | "AUTH" | "GENERATING" | "INTERACTIVE";
+type BusyStep = Exclude<Step, "SELECT" | "INTERACTIVE">;
 
-const STEP_MESSAGE: Record<Exclude<Step, "SELECT" | "INTERACTIVE">, string> = {
-  CONNECTING: "Connecting to anchor…",
-  AUTH: "Waiting for wallet signature…",
-  GENERATING: "Preparing your deposit form…",
+const STEP_MESSAGE_KEY: Record<BusyStep, "stepConnecting" | "stepAuth" | "stepGenerating"> = {
+  CONNECTING: "stepConnecting",
+  AUTH: "stepAuth",
+  GENERATING: "stepGenerating",
 };
 
 export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProps) {
+  const t = useTranslations("fiatOnramp");
   const [step, setStep] = useState<Step>("SELECT");
   const [amount, setAmount] = useState("");
   const [anchorDomain, setAnchorDomain] = useState(DEFAULT_ANCHOR);
@@ -96,15 +99,15 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
       setInteractiveUrl(url);
       setStep("INTERACTIVE");
     } catch (err) {
-      const message = err instanceof Error ? err.message : "Deposit failed";
+      const message = err instanceof Error ? err.message : t("genericError");
       toast.error(message);
       setError(message);
       setStep("SELECT");
     }
-  }, [anchorDomain, amount, selectedAsset]);
+  }, [anchorDomain, amount, selectedAsset, t]);
 
   return (
-    <Modal isOpen={isOpen} onClose={handleClose} title="Buy / Deposit Funds">
+    <Modal isOpen={isOpen} onClose={handleClose} title={t("title")}>
       <AnimatePresence mode="wait">
         {step === "SELECT" && (
           <motion.div
@@ -115,10 +118,7 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
             transition={{ duration: 0.18 }}
             className="flex flex-col gap-6"
           >
-            <p className="text-sm text-slate-400">
-              Deposit fiat via a Stellar anchor (SEP-0024). Funds arrive as tokens directly
-              in your connected wallet.
-            </p>
+            <p className="text-sm text-slate-400">{t("description")}</p>
 
             {error && (
               <div
@@ -131,7 +131,7 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
 
             <div className="space-y-2">
               <label className="text-xs font-semibold uppercase tracking-wider text-slate-500">
-                Select Asset
+                {t("selectAsset")}
               </label>
               <div className="grid grid-cols-2 gap-4">
                 {SUPPORTED_ASSETS.map((asset) => (
@@ -158,7 +158,7 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
 
             <div className="space-y-2">
               <label htmlFor="onramp-amount" className="text-xs font-semibold uppercase tracking-wider text-slate-500">
-                Amount <span className="normal-case text-slate-600">(optional)</span>
+                {t("amountLabel")} <span className="normal-case text-slate-600">{t("amountOptional")}</span>
               </label>
               <input
                 id="onramp-amount"
@@ -168,13 +168,13 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
                 onChange={(e) => setAmount(e.target.value)}
                 disabled={isBusy}
                 className="w-full rounded-xl border border-white/10 bg-black/40 px-4 py-3 text-sm text-white focus:outline-none focus:ring-1 focus:ring-mint disabled:cursor-not-allowed disabled:opacity-50"
-                placeholder={`e.g. 100 ${selectedAsset.code}`}
+                placeholder={t("amountPlaceholder", { amount: "100", asset: selectedAsset.code })}
               />
             </div>
 
             <div className="space-y-2">
               <label htmlFor="onramp-anchor" className="text-xs font-semibold uppercase tracking-wider text-slate-500">
-                Anchor Domain
+                {t("anchorDomainLabel")}
               </label>
               <input
                 id="onramp-anchor"
@@ -183,7 +183,7 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
                 onChange={(e) => setAnchorDomain(e.target.value)}
                 disabled={isBusy}
                 className="w-full rounded-xl border border-white/10 bg-black/40 px-4 py-3 text-sm text-white focus:outline-none focus:ring-1 focus:ring-mint disabled:cursor-not-allowed disabled:opacity-50"
-                placeholder="e.g. testanchor.stellar.org"
+                placeholder={t("anchorDomainPlaceholder")}
               />
             </div>
 
@@ -196,10 +196,10 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
               {isBusy ? (
                 <>
                   <Spinner size="sm" className="text-black" />
-                  {STEP_MESSAGE[step as Exclude<Step, "SELECT" | "INTERACTIVE">]}
+                  {t(STEP_MESSAGE_KEY[step as BusyStep])}
                 </>
               ) : (
-                "Continue to Anchor"
+                t("continueButton")
               )}
             </button>
           </motion.div>
@@ -222,11 +222,9 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
                 <Spinner size="lg" className="text-mint" />
               </div>
             </div>
-            <h3 className="text-lg font-bold text-white">{STEP_MESSAGE[step]}</h3>
+            <h3 className="text-lg font-bold text-white">{t(STEP_MESSAGE_KEY[step as BusyStep])}</h3>
             <p className="mt-2 text-sm text-slate-400">
-              {step === "AUTH"
-                ? `Please sign the challenge transaction in your wallet to securely connect to ${anchorDomain}.`
-                : "This should only take a moment."}
+              {step === "AUTH" ? t("authHint", { domain: anchorDomain }) : t("genericHint")}
             </p>
           </motion.div>
         )}
@@ -249,7 +247,7 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
             )}
             <iframe
               src={interactiveUrl}
-              title="Anchor deposit form"
+              title={t("iframeTitle")}
               className="h-full w-full"
               onLoad={() => setIframeLoading(false)}
             />
@@ -258,9 +256,7 @@ export default function FiatOnrampModal({ isOpen, onClose }: FiatOnrampModalProp
       </AnimatePresence>
 
       {step !== "INTERACTIVE" && (
-        <p className="mt-6 text-center text-xs text-slate-500">
-          Secured by Stellar Network • SEP-0024 Standard
-        </p>
+        <p className="mt-6 text-center text-xs text-slate-500">{t("footerNote")}</p>
       )}
     </Modal>
   );