feat: connect django admin smoke tests

apps/users/tests.py

@@ -1,3 +1,23 @@
+from django.contrib import admin
+from django.contrib.auth import get_user_model
 from django.test import TestCase
+from django.urls import reverse
 
-# Create your tests here.
+
+class AdminSmokeTests(TestCase):
+    def test_custom_user_is_registered_in_admin(self):
+        self.assertIn(get_user_model(), admin.site._registry)
+
+    def test_superuser_can_login_to_admin(self):
+        user_model = get_user_model()
+        user_model.objects.create_superuser(
+            username="admin",
+            email="admin@example.com",
+            password="test-password",
+        )
+
+        logged_in = self.client.login(username="admin", password="test-password")
+        self.assertTrue(logged_in)
+
+        response = self.client.get(reverse("admin:index"))
+        self.assertEqual(response.status_code, 200)