Replace model iframe with Vercel rewrite

app/src/WebsiteRouter.tsx

@@ -24,7 +24,6 @@ const BrandWritingPage = lazy(() => import('./pages/BrandWriting.page'));
 const ClaudePluginsPage = lazy(() => import('./pages/ClaudePlugins.page'));
 const DonatePage = lazy(() => import('./pages/Donate.page'));
 const OrgLogosEmbedPage = lazy(() => import('./pages/embed/OrgLogosEmbed.page'));
-const ModelPage = lazy(() => import('./pages/Model.page'));
 const PrivacyPage = lazy(() => import('./pages/Privacy.page'));
 const ResearchPage = lazy(() => import('./pages/Research.page'));
 const SupportersPage = lazy(() => import('./pages/Supporters.page'));
@@ -38,6 +37,13 @@ function BlogRedirect() {
   return <Navigate to={`../research/${postName}`} replace />;
 }
 
+// Full-page redirect to /model (handled by Vercel rewrite, not React Router)
+function MethodologyRedirect() {
+  const { countryId } = useParams();
+  window.location.replace(`/${countryId}/model`);
+  return null;
+}
+
 const router = createBrowserRouter(
   [
     {
@@ -82,7 +88,7 @@ const router = createBrowserRouter(
                 },
                 {
                   path: 'methodology',
-                  element: <Navigate to="../model" replace />,
+                  element: <MethodologyRedirect />,
                 },
                 {
                   path: 'support',
@@ -120,10 +126,6 @@ const router = createBrowserRouter(
                   path: 'ai-inequality',
                   element: <AIGrowthResearchPage />,
                 },
-                {
-                  path: 'model',
-                  element: <ModelPage />,
-                },
                 {
                   path: 'claude-plugin',
                   element: <ClaudePluginsPage />,

app/src/components/homeHeader/NavItem.tsx

@@ -15,6 +15,8 @@ export interface NavItemSetup {
   href?: string;
   hasDropdown: boolean;
   dropdownItems?: DropdownItem[];
+  /** Force full page load instead of SPA navigation (for Vercel-rewritten routes) */
+  reloadDocument?: boolean;
 }
 
 interface NavItemProps {
@@ -184,7 +186,7 @@ function AppleDropdown({
  * Can be either a simple link or a dropdown menu.
  */
 export default function NavItem({ setup }: NavItemProps) {
-  const { label, onClick, href, hasDropdown, dropdownItems } = setup;
+  const { label, onClick, href, hasDropdown, dropdownItems, reloadDocument } = setup;
   const [dropdownOpen, setDropdownOpen] = useState(false);
   const containerRef = useRef<HTMLDivElement>(null);
 
@@ -259,7 +261,7 @@ export default function NavItem({ setup }: NavItemProps) {
   // Relative paths use React Router's Link for SPA behavior
   if (isInternalHref(href)) {
     return (
-      <Link to={href} style={navItemStyle} {...hoverHandlers}>
+      <Link to={href} reloadDocument={reloadDocument} style={navItemStyle} {...hoverHandlers}>
         {label}
       </Link>
     );

app/src/components/shared/HomeHeader.tsx

@@ -23,6 +23,7 @@ export default function HeaderNavigation({ navbarOpened, onToggleNavbar }: Heade
       label: 'Model',
       href: getWebsitePath('/model'),
       hasDropdown: false,
+      reloadDocument: true,
     },
     {
       label: 'About',

vercel.json

@@ -77,6 +77,10 @@
       "source": "/us/taxsim/:path*",
       "destination": "https://policyengine-taxsim-policy-engine.vercel.app/us/taxsim/:path*"
     },
+    {
+      "source": "/:countryId/model",
+      "destination": "https://policyengine-model.vercel.app/?country=:countryId"
+    },
     { "source": "/(.*)", "destination": "/website.html" }
   ],
   "headers": [