default: deny all, through a folder app of its own

apps/templates/default-folder.yaml

@@ -0,0 +1,19 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: default-folder
+  namespace: argocd
+  finalizers:
+  - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+  source:
+    repoURL: https://github.com/rubenhensen/k8scd.git
+    targetRevision: HEAD
+    path: default
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: default
+  syncPolicy:
+    automated:
+      selfHeal: true

default/networkpolicy.yaml

@@ -0,0 +1,14 @@
+# Nothing runs in default (2026-10-26: only the kubernetes Service, whose
+# endpoint is the API server on the node, which this doesn't touch). A pod
+# started here, by `kubectl run` or a manifest without a namespace, gets
+# no network at all, instead of reaching the LAN, Vault and every app.
+# Anything that needs a network gets a namespace and a policy of its own.
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: default-deny
+spec:
+  podSelector: {}
+  policyTypes:
+    - Ingress
+    - Egress