fix: vendor user now lands on /vendor/tenants after login

LandingRedirect component checks scopes — platform:admin goes to
vendor console, others go to tenant dashboard.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/router.tsx

@@ -5,6 +5,7 @@ import { ProtectedRoute } from './auth/ProtectedRoute';
 import { OrgResolver } from './auth/OrgResolver';
 import { Layout } from './components/Layout';
 import { RequireScope } from './components/RequireScope';
+import { useScopes } from './auth/useScopes';
 
 import { VendorTenantsPage } from './pages/vendor/VendorTenantsPage';
 import { CreateTenantPage } from './pages/vendor/CreateTenantPage';
@@ -15,6 +16,14 @@ import { OidcConfigPage } from './pages/tenant/OidcConfigPage';
 import { TeamPage } from './pages/tenant/TeamPage';
 import { SettingsPage } from './pages/tenant/SettingsPage';
 
+function LandingRedirect() {
+  const scopes = useScopes();
+  if (scopes.has('platform:admin')) {
+    return <Navigate to="/vendor/tenants" replace />;
+  }
+  return <Navigate to="/tenant" replace />;
+}
+
 export function AppRouter() {
   return (
     <Routes>
@@ -47,8 +56,8 @@ export function AppRouter() {
             <Route path="/tenant/team" element={<TeamPage />} />
             <Route path="/tenant/settings" element={<SettingsPage />} />
 
-            {/* Default redirect */}
-            <Route index element={<Navigate to="/tenant" replace />} />
+            {/* Default redirect — vendor goes to /vendor/tenants, customer to /tenant */}
+            <Route index element={<LandingRedirect />} />
           </Route>
         </Route>
       </Route>