Fix STATIC_ROOT configuration and improve production settings

- Add STATIC_ROOT and MEDIA_ROOT settings with environment variable support
- Update settings.py to use environment variables for SECRET_KEY, DEBUG, ALLOWED_HOSTS, TIME_ZONE
- Improve docker-entrypoint.sh to auto-create static/media directories
- Always run collectstatic in Docker (not just production)
- Add check_settings.py script for configuration verification
- Add PRODUCTION_CHECKLIST.md for deployment guide
- Update .env.example with all configuration options
- Update .gitignore for proper static/media file handling

This fixes the ImproperlyConfigured error when deploying with Docker.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.gitignore

@@ -56,8 +56,8 @@ venv.bak/
 local_settings.py
 db.sqlite3
 db.sqlite3-journal
-media/
-staticfiles/
+/mediafiles/
+/staticfiles/
 
 # Environment variables
 .env