fix: missing ID in create gateway response

Signed-off-by: Tomas Pilar <[email protected]>

Author: pilartomas

mcpgateway/services/gateway_service.py

@@ -386,7 +386,7 @@ async def register_gateway(self, db: Session, gateway: GatewayCreate) -> Gateway
             # Notify subscribers
             await self._notify_gateway_added(db_gateway)
 
-            return GatewayRead.model_validate(gateway)
+            return GatewayRead.model_validate(db_gateway)
         except* GatewayConnectionError as ge:
             if TYPE_CHECKING:
                 ge: ExceptionGroup[GatewayConnectionError]