fix(web): auto-refresh 401s + restore Vietnamese breadcrumb text

- api-client: on 401 (non-auth endpoints), call /auth/refresh once and
  retry the original request. Coalesce concurrent refreshes via a shared
  in-flight promise so burst traffic only fires one refresh. Skip retry
  for /auth/* to avoid loops. Surfaced by the /listings/new wizard
  where an expired access_token cookie made the first submit throw
  "Unauthorized" even though goodgo_authenticated=1 was still set.
- listing-detail-client: breadcrumb was `Trang ch\u1ee7` / `T\u00ecm
  ki\u1ebfm` written as JSX text, not a string literal — rendered the
  raw escape sequence. Replaced with "Trang chủ" / "Tìm kiếm".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/components/listings/listing-detail-client.tsx

@@ -81,9 +81,9 @@ export function ListingDetailClient({ listing }: ListingDetailClientProps) {
     <div className="mx-auto max-w-6xl px-4 py-6">
       {/* Breadcrumb */}
       <nav className="mb-4 flex items-center gap-1.5 text-sm text-muted-foreground">
-        <Link href="/" className="hover:text-foreground">Trang ch\u1ee7</Link>
+        <Link href="/" className="hover:text-foreground">Trang chủ</Link>
         <span>/</span>
-        <Link href="/search" className="hover:text-foreground">T\u00ecm ki\u1ebfm</Link>
+        <Link href="/search" className="hover:text-foreground">Tìm kiếm</Link>
         <span>/</span>
         <span className="truncate text-foreground">{property.title}</span>
       </nav>

apps/web/lib/api-client.ts

@@ -22,7 +22,52 @@ function getCsrfToken(): string | undefined {
 
 const SAFE_METHODS = new Set(['GET', 'HEAD', 'OPTIONS']);
 
-async function request<T>(endpoint: string, options: RequestOptions = {}): Promise<T> {
+// Endpoints for which a transparent refresh-and-retry on 401 must NOT run
+// (refresh itself, login, logout, exchange-token, etc.).
+const AUTH_ENDPOINTS = new Set([
+  '/auth/refresh',
+  '/auth/login',
+  '/auth/logout',
+  '/auth/register',
+  '/auth/exchange-token',
+  '/auth/forgot-password',
+  '/auth/reset-password',
+]);
+
+/**
+ * Coalesce concurrent refresh attempts: if ten requests race a 401 at the same
+ * moment, we should fire `/auth/refresh` once, not ten times.
+ */
+let refreshInflight: Promise<boolean> | null = null;
+
+async function tryRefresh(): Promise<boolean> {
+  if (refreshInflight) return refreshInflight;
+  refreshInflight = (async () => {
+    try {
+      const csrfToken = getCsrfToken();
+      const res = await fetch(`${API_BASE_URL}/auth/refresh`, {
+        method: 'POST',
+        credentials: 'include',
+        headers: {
+          'Content-Type': 'application/json',
+          ...(csrfToken ? { 'X-CSRF-Token': csrfToken } : {}),
+        },
+        body: JSON.stringify({}),
+      });
+      return res.ok;
+    } catch {
+      return false;
+    } finally {
+      // Allow a new refresh attempt after this one settles.
+      setTimeout(() => {
+        refreshInflight = null;
+      }, 0);
+    }
+  })();
+  return refreshInflight;
+}
+
+async function doFetch(endpoint: string, options: RequestOptions): Promise<Response> {
   const { body, headers, ...rest } = options;
   const method = options.method?.toUpperCase() ?? 'GET';
 
@@ -34,7 +79,7 @@ async function request<T>(endpoint: string, options: RequestOptions = {}): Promi
     }
   }
 
-  const res = await fetch(`${API_BASE_URL}${endpoint}`, {
+  return fetch(`${API_BASE_URL}${endpoint}`, {
     ...rest,
     credentials: 'include',
     headers: {
@@ -44,6 +89,19 @@ async function request<T>(endpoint: string, options: RequestOptions = {}): Promi
     },
     body: body ? JSON.stringify(body) : undefined,
   });
+}
+
+async function request<T>(endpoint: string, options: RequestOptions = {}): Promise<T> {
+  let res = await doFetch(endpoint, options);
+
+  // If the access_token expired silently, try one refresh+retry before giving
+  // up. Skip for auth endpoints themselves to avoid loops.
+  if (res.status === 401 && !AUTH_ENDPOINTS.has(endpoint)) {
+    const refreshed = await tryRefresh();
+    if (refreshed) {
+      res = await doFetch(endpoint, options);
+    }
+  }
 
   if (!res.ok) {
     const error = await res.json().catch(() => ({ message: res.statusText }));