Format code with Black and isort for CI/CD compliance

- Apply Black formatting to all Python files in core and stiftung modules
- Fix import statement ordering with isort
- Ensure all code meets automated quality standards
- Resolve CI/CD pipeline formatting failures
- Maintain consistent code style across the entire codebase

app/core/asgi.py

@@ -1,4 +1,6 @@
 import os
+
 from django.core.asgi import get_asgi_application
-os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'core.settings')
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "core.settings")
 application = get_asgi_application()