Initial commit: Django project with boxes app

- Set up Django 5.2.9 project structure
- Add boxes app with Box and BoxType models
- Box: alphanumeric ID (max 10 chars) with foreign key to BoxType
- BoxType: name and dimensions (width/height/length in mm)
- Configure admin interface for both models
- Add comprehensive test suite (14 tests)

boxes/apps.py

@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class BoxesConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'boxes'