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)

app/Http/Controllers/CheckoutGoogleController.php

@@ -91,7 +91,9 @@ class CheckoutGoogleController extends Controller
             $tenant = $this->createTenantForUser($user, $googleUser->getName(), $email);
 
             try {
-                Mail::to($user)->queue(new Welcome($user));
+                Mail::to($user)
+                    ->locale($user->preferred_locale ?? app()->getLocale())
+                    ->queue(new Welcome($user));
             } catch (\Throwable $exception) {
                 Log::warning('Failed to queue welcome mail after Google signup', [
                     'user_id' => $user->id,