Add backlogger app at /backlogger/ with login protection

Django app with Item model (games/books/films/other categories), CRUD
views, and login-required access. Login page at /accounts/login/ uses
custom dark-themed template consistent with the site design.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

kboris/urls.py

@@ -1,7 +1,11 @@
 from django.contrib import admin
+from django.contrib.auth import views as auth_views
 from django.urls import path, include
 
 urlpatterns = [
     path('admin/', admin.site.urls),
+    path('accounts/login/', auth_views.LoginView.as_view(template_name='backlogger/login.html'), name='login'),
+    path('accounts/logout/', auth_views.LogoutView.as_view(), name='logout'),
+    path('backlogger/', include('backlogger.urls')),
     path('', include('core.urls')),
 ]