Fix tenant event form package selector so it no longer renders empty-value options, handles loading/empty

states, and pulls data from the authenticated /api/v1/tenant/packages endpoint.
    (resources/js/admin/pages/EventFormPage.tsx, resources/js/admin/api.ts)
  - Harden tenant-admin auth flow: prevent PKCE state loss, scope out StrictMode double-processing, add SPA
    routes for /event-admin/login and /event-admin/logout, and tighten token/session clearing semantics (resources/js/admin/auth/{context,tokens}.tsx, resources/js/admin/pages/{AuthCallbackPage,LogoutPage}.tsx,
    resources/js/admin/router.tsx, routes/web.php)

resources/lang/en/marketing.php

@@ -160,4 +160,7 @@ return [
     'currency' => [
         'euro' => '€',
     ],
+    'contact' => [
+        'success' => 'Thanks! We will get back to you soon.',
+    ],
 ];