Add scheduled automation task and update URL routing

- Introduced a new scheduled task for executing automation rules every 5 minutes in the Celery beat schedule.
- Updated URL routing to include a new endpoint for automation-related functionalities.
- Refactored imports in various modules to align with the new business layer structure, ensuring backward compatibility for billing models, exceptions, and services.

backend/igny8_core/business/billing/exceptions.py

@@ -0,0 +1,14 @@
+"""
+Billing Exceptions
+"""
+
+
+class InsufficientCreditsError(Exception):
+    """Raised when account doesn't have enough credits"""
+    pass
+
+
+class CreditCalculationError(Exception):
+    """Raised when credit calculation fails"""
+    pass
+