docs: A-4 — a dead pod reports healthier than a live one

Kubernetes keeps calling the node Ready for forty seconds while users already see failures, and the pod on the powered-off machine stays ready=true because its kubelet can no longer contradict itself. Eviction waits another five minutes, then the StatefulSet refuses to recreate its pod and the replacement Deployment pod cannot schedule because the local-path volume is pinned to the dead node.

Killing the server node instead shows the opposite shape: containerd keeps the workload running while the API server, Traefik and the observability stack disappear, so the outage is the missing path rather than the missing application. Traefik at one replica is the ingress single point of failure.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/evidence/a4-node-loss/06-control-plane-inventory.txt

@@ -0,0 +1,19 @@
+=== 복구 확인 ===
+keycloak-0                  1/1   Running   0     68s
+keycloak-1                  1/1   Running   0     144m
+postgres-7b474b88c8-9cmsv   1/1   Running   0     4m20s
+
+=== kc-lab-1(k3s server)에 무엇이 있는가 — 이게 곧 영향 범위다 ===
+  keycloak-lab     keycloak-1
+  kube-system      coredns-54996dc9b4-8k8fj
+  kube-system      helm-install-traefik-crd-q29b5
+  kube-system      local-path-provisioner-77b9867795-g27z8
+  kube-system      metrics-server-6dc596dfb8-7xxq4
+  kube-system      svclb-traefik-5eb6a9a1-qwwk5
+  kube-system      traefik-5d6fcf895-wpfhr
+  observability    grafana-845b5678cf-b6gvc
+  observability    node-exporter-9qk9w
+  observability    prometheus-6774f94f7c-pzr2t
+
+=== Traefik replica 수 (진입점의 단일 장애점인가) ===
+traefik   1     1