Refactor user account system and remove moderation integration

- Remove first_name and last_name fields from User model
- Add user deletion and social provider services
- Restructure auth serializers into separate directory
- Update avatar upload functionality and API endpoints
- Remove django-moderation integration documentation
- Add mandatory compliance enforcement rules
- Update frontend documentation with API usage examples

backend/pyproject.toml

@@ -60,6 +60,7 @@ dependencies = [
     "celery>=5.5.3",
     "django-celery-beat>=2.8.1",
     "django-celery-results>=2.6.0",
+    "djangorestframework-simplejwt>=5.5.1",
 ]
 
 [dependency-groups]