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)

.gitignore

@@ -0,0 +1,18 @@
+__pycache__/
+**/*.pyc
+lib/
+lib64
+bin/
+pyvenv.cfg
+include/
+keys/
+.venv/
+.idea/
+*.kate-swp
+node_modules/
+package-lock.json
+package.json
+AGENT*.md
+# Diagram cache directory
+.env
+data/db.sqlite3