feat(src/djinit/utils): add use_django_q and use_celery to metadata dictionary

Add configurable flags for enabling Django Q and Celery in generated projects.

New Features:
- Introduce `use_django_q` and `use_celery` entries in the metadata dictionary, defaulting to False when unspecified.
- Allow downstream code to conditionally activate these features based on user configuration.

Enhancements:
- Extend the metadata schema to support additional Django ecosystem integrations.

src/djinit/utils/django.py

@@ -49,6 +49,8 @@ class DjangoHelper:
                 "use_vite": metadata.get("use_vite", False),
                 "use_vue": metadata.get("use_vue", False),
                 "use_pytest": metadata.get("use_pytest", False),
+                "use_django_q": metadata.get("use_django_q", False),
+                "use_celery": metadata.get("use_celery", False),
             }
 
             dev_context = {"secret_key": secret_key}