feat: add marketplace metrics, privacy features, and service registry endpoints

- Add Prometheus metrics for marketplace API throughput and error rates with new dashboard panels
- Implement confidential transaction models with encryption support and access control
- Add key management system with registration, rotation, and audit logging
- Create services and registry routers for service discovery and management
- Integrate ZK proof generation for privacy-preserving receipts
- Add metrics instru

enterprise-connectors/python-sdk/aitbc_enterprise/exceptions.py

@@ -0,0 +1,68 @@
+"""
+Exception classes for AITBC Enterprise Connectors
+"""
+
+
+class AITBCError(Exception):
+    """Base exception for all AITBC errors"""
+    pass
+
+
+class AuthenticationError(AITBCError):
+    """Raised when authentication fails"""
+    pass
+
+
+class RateLimitError(AITBCError):
+    """Raised when rate limit is exceeded"""
+    def __init__(self, message: str, retry_after: int = None):
+        super().__init__(message)
+        self.retry_after = retry_after
+
+
+class APIError(AITBCError):
+    """Raised when API request fails"""
+    def __init__(self, message: str, status_code: int = None, response: dict = None):
+        super().__init__(message)
+        self.status_code = status_code
+        self.response = response
+
+
+class ConfigurationError(AITBCError):
+    """Raised when configuration is invalid"""
+    pass
+
+
+class ConnectorError(AITBCError):
+    """Raised when connector operation fails"""
+    pass
+
+
+class PaymentError(ConnectorError):
+    """Raised when payment operation fails"""
+    pass
+
+
+class ValidationError(AITBCError):
+    """Raised when data validation fails"""
+    pass
+
+
+class WebhookError(AITBCError):
+    """Raised when webhook processing fails"""
+    pass
+
+
+class ERPError(ConnectorError):
+    """Raised when ERP operation fails"""
+    pass
+
+
+class SyncError(ConnectorError):
+    """Raised when synchronization fails"""
+    pass
+
+
+class TimeoutError(AITBCError):
+    """Raised when operation times out"""
+    pass