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/settings.py

@@ -29,8 +29,12 @@ INSTALLED_APPS = [
     'whitenoise.runserver_nostatic',
     'django.contrib.staticfiles',
     'core',
+    'backlogger',
 ]
 
+LOGIN_REDIRECT_URL = '/backlogger/'
+LOGOUT_REDIRECT_URL = '/'
+
 MIDDLEWARE = [
     'django.middleware.security.SecurityMiddleware',
     'whitenoise.middleware.WhiteNoiseMiddleware',