add source code and readme

manifests/infrastructure/tailscale/old-subnet-router/kustomization.yaml

@@ -0,0 +1,12 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+- namespace.yaml
+# Legacy resources (not currently used - operator manages these now)
+# - auth-secret.yaml
+# - service-account.yaml
+# - rbac.yaml
+# - subnet-router-deployment.yaml
+# Operator-based resources
+- operator-helm/