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>

backlogger/models.py

@@ -0,0 +1,39 @@
+from django.db import models
+
+
+class Item(models.Model):
+    GAMES = 'games'
+    BOOKS = 'books'
+    FILMS = 'films'
+    OTHER = 'other'
+    CATEGORY_CHOICES = [
+        (GAMES, 'Games'),
+        (BOOKS, 'Books'),
+        (FILMS, 'Films'),
+        (OTHER, 'Other'),
+    ]
+
+    category = models.CharField(max_length=10, choices=CATEGORY_CHOICES)
+    name = models.CharField(max_length=200)
+    progress_percent = models.FloatField(default=0.0)
+    favorite = models.BooleanField(default=False)
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    # Games
+    hours_played = models.FloatField(null=True, blank=True)
+    total_hours = models.FloatField(null=True, blank=True)
+
+    # Books
+    pages_read = models.IntegerField(null=True, blank=True)
+    total_pages = models.IntegerField(null=True, blank=True)
+
+    # Films
+    watched = models.BooleanField(null=True, blank=True)
+    duration_minutes = models.IntegerField(null=True, blank=True)
+
+    class Meta:
+        ordering = ['-favorite', 'name']
+
+    def __str__(self):
+        return f"{self.get_category_display()}: {self.name}"