Remove nessus app and fix envoy-gateway OCI chart bug

- Delete nessus Application CRD, manifests, and bootstrap script
- Vendor envoy-gateway Helm chart (v1.6.3) locally to work around
  ArgoCD v3.3.3 Docker Hub OCI resolution bug
- Re-enable auto-sync for envoy-gateway

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

argocd-apps/infrastructure/envoy-gateway.yaml

@@ -10,9 +10,11 @@ metadata:
 spec:
   project: infrastructure
   sources:
-    - repoURL: oci://docker.io/envoyproxy
-      chart: gateway-helm
-      targetRevision: v1.6.3
+    # Vendored chart from oci://docker.io/envoyproxy/gateway-helm v1.6.3
+    # (ArgoCD v3.3.3 has OCI resolution bug with Docker Hub)
+    - repoURL: https://gitlab.kube.huskypup.net/Scooby/Homelabv4.git
+      targetRevision: main
+      path: charts/envoy-gateway
       helm:
         valueFiles:
           - $values/infrastructure/envoy-gateway/values.yaml
@@ -22,10 +24,10 @@ spec:
   destination:
     server: https://kubernetes.default.svc
     namespace: envoy-gateway-system
-  # NOTE: Auto-sync disabled due to ArgoCD v3.3.3 OCI chart resolution bug
-  # (HEAD request to Docker Hub doesn't include chart name in OCI path)
-  # Re-enable after upgrading ArgoCD or when the bug is fixed
   syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
     syncOptions:
       - CreateNamespace=true
       - ServerSideApply=true