feat: enhance header context handling and add login page test

- Updated `header.html` to use `with` block for `active` context variable fallback
- Added test to verify login page renders correctly without `active` context

templates/_fragments/header.html

@@ -1,4 +1,5 @@
 <!-- HEADER FRAGMENT -->
+{% with active=active|default:'' %}
 <header>
     <div class="container">
         <div class="header-top">
@@ -72,3 +73,4 @@
         </nav>
     </div>
 </header>
+{% endwith %}

users/tests.py

@@ -12,6 +12,12 @@ User = get_user_model()
 
 @override_settings(EMAIL_BACKEND="django.core.mail.backends.locmem.EmailBackend")
 class UserAuthFlowTests(TestCase):
+    def test_login_page_renders_without_active_context(self):
+        response = self.client.get(reverse("users:login"))
+
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(response, "users/login.html")
+
     def test_registration_creates_inactive_user_and_sends_activation_email(self):
         response = self.client.post(
             reverse("users:register"),