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)

database/seeders/OAuthClientSeeder.php

@@ -18,7 +18,7 @@ class OAuthClientSeeder extends Seeder
         $serviceConfig = config('services.oauth.tenant_admin', []);
 
         $clientId = $serviceConfig['id'] ?? 'tenant-admin-app';
-        $tenantId = Tenant::where('slug', 'demo')->value('id')
+        $tenantId = Tenant::where('slug', 'demo-tenant')->value('id')
             ?? Tenant::query()->orderBy('id')->value('id');
 
         $redirectUris = Arr::wrap($serviceConfig['redirects'] ?? []);