docs: Add logging infrastructure guide for Kubernetes deployments

- Add comprehensive logging infrastructure documentation covering standard and audit logs
- Document log format specifications with field definitions
- Include configuration examples for operator and MCPServer resources
- Add log collection strategies and enterprise tool integration (ELK, Splunk, Datadog)
- Update sidebar navigation to include the new guide
- Add contextual reference from deploy-operator-helm.md

Addresses: stacklok/toolhive-platform#39

Author: JAORMX

docs/toolhive/guides-k8s/deploy-operator-helm.md

@@ -70,7 +70,8 @@ kubectl logs -f -n toolhive-system <TOOLHIVE_OPERATOR_POD_NAME>
 ```
 
 This shows you the logs of the operator pod, which can help you debug any
-issues.
+issues. For comprehensive logging and audit capabilities, see the
+[Logging infrastructure](./logging-infrastructure.md) guide.
 
 ## Customize the operator