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>