- Reworked the tenant admin login page

- Updated the User model to implement Filament’s tenancy contracts
- Seeded a ready-to-use demo tenant (user, tenant, active package, purchase)
- Introduced a branded, translated 403 error page to replace the generic forbidden message for unauthorised admin hits
- Removed the public “Register” links from the marketing header
- hardened join event logic and improved error handling in the guest pwa.

database/seeders/DatabaseSeeder.php

@@ -29,6 +29,7 @@ class DatabaseSeeder extends Seeder
         // Seed demo and admin data
         $this->call([
             SuperAdminSeeder::class,
+            DemoTenantSeeder::class,
             DemoEventSeeder::class,
             OAuthClientSeeder::class,
         ]);