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

infra/k8s/default-deny-netpol.yaml

@@ -0,0 +1,56 @@
+# Default Deny All Network Policy
+# This policy denies all ingress and egress traffic by default
+# Individual services must have their own network policies to allow traffic
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: default-deny-all-ingress
+  namespace: default
+spec:
+  podSelector: {}
+  policyTypes:
+  - Ingress
+---
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: default-deny-all-egress
+  namespace: default
+spec:
+  podSelector: {}
+  policyTypes:
+  - Egress
+---
+# Allow DNS resolution for all pods
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: allow-dns
+  namespace: default
+spec:
+  podSelector: {}
+  policyTypes:
+  - Egress
+  egress:
+  - to: []
+    ports:
+    - protocol: UDP
+      port: 53
+    - protocol: TCP
+      port: 53
+---
+# Allow traffic to Kubernetes API
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: allow-k8s-api
+  namespace: default
+spec:
+  podSelector: {}
+  policyTypes:
+  - Egress
+  egress:
+  - to: []
+    ports:
+    - protocol: TCP
+      port: 443