Refactor authentication and integration handling

- Exclude the 'MeView' endpoint from public API documentation, marking it as an internal authenticated endpoint.
- Enhance error handling in the 'IntegrationSettingsViewSet' to gracefully manage empty request data and improve logging for account and settings lookups.
- Update API key retrieval logic to ensure fallback mechanisms are more robust and informative.
- Refactor user data fetching in the auth store to utilize a unified API system, improving error handling and data consistency.

backend/igny8_core/auth/urls.py

@@ -180,11 +180,7 @@ class ChangePasswordView(APIView):
         )
 
 
-@extend_schema(
-    tags=['Authentication'],
-    summary='Get Current User',
-    description='Get information about the currently authenticated user'
-)
+@extend_schema(exclude=True)  # Exclude from public API documentation - internal authenticated endpoint
 class MeView(APIView):
     """Get current user information."""
     permission_classes = [permissions.IsAuthenticated]