Make demo login gate backend-authoritative

frontend/src/router.ts

@@ -4,7 +4,7 @@ import { useAuthStore } from './stores/auth'
 import { useAwardsStore } from './stores/awards'
 import { routes } from './router/routes'
 
-const DEMO_GATE_HARD_DISABLED = import.meta.env.VITE_DEMO_GATE_ENABLED === 'false'
+const DEMO_GATE_FALLBACK_ENABLED = import.meta.env.VITE_DEMO_GATE_ENABLED !== 'false'
 const contentAdminRoutes = new Set(['admin-content', 'admin-settings'])
 
 const router = createRouter({
@@ -35,7 +35,9 @@ router.beforeEach(async (to) => {
   const isAdminRoute = to.path.startsWith('/admin')
   const isMaintenancePreview = isMaintenanceRoute && to.query.preview === 'true'
   const siteStatus = await loadSiteStatus()
-  const demoGateEnabled = !DEMO_GATE_HARD_DISABLED && siteStatus?.demoLoginEnabled !== false
+  const demoGateEnabled = siteStatus
+    ? siteStatus.demoLoginEnabled
+    : DEMO_GATE_FALLBACK_ENABLED
 
   if (isMaintenancePreview && !authStore.isAdmin) {
     return { name: 'login', query: { redirect: to.fullPath } }