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/01-baseline.txt

@@ -0,0 +1,20 @@
+=== A-4 기준선 ===
+kc-lab-1   Ready   true
+kc-lab-2   Ready   <none>
+
+a2-probe                    true   kc-lab-2
+keycloak-0                  true   kc-lab-2
+keycloak-1                  true   kc-lab-1
+postgres-7b474b88c8-2gf27   true   kc-lab-2
+
+=== PVC 가 어느 노드에 묶여 있는가 (재배치 가능성) ===
+  persistentvolumeclaim/postgres-data → kc-lab-2
+
+=== 서비스 정상 확인 ===
+  https://auth.hyeonworks.com/realms/master  HTTP 200
+
+=== VM 상태 ===
+--------------------------
+ 1    kc-lab-1   running
+ 2    kc-lab-2   running
+