Add Harbor/Ceph runbooks and align single-node Ceph docs with abr deployment.

Document registry ingress split, image mirroring, loop OSD setup, and platform integration paths.

backend/helm/cloudhost-ceph/templates/integration-configmap.yaml

@@ -0,0 +1,20 @@
+{{- if .Values.integration.createConfigMap }}
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ .Values.integration.configMapName }}
+  namespace: {{ .Values.namespace }}
+  labels:
+    {{- include "cloudhost-ceph.labels" . | nindent 4 }}
+data:
+  PLATFORM_STORAGE_CLASS: rook-ceph-block
+  PLATFORM_CREATE_STORAGE_CLASS: "false"
+  PLATFORM_STORAGE_PROVISIONER: rook-ceph.rbd.csi.ceph.com
+  SOURCE_STORAGE_ENDPOINT: {{ .Values.platform.endpoint | quote }}
+  SOURCE_STORAGE_REGION: {{ .Values.platform.region | quote }}
+  SOURCE_STORAGE_CREDENTIALS_SECRET: {{ .Values.platform.credentialsSecretName | quote }}
+  README: |
+    Block PVCs: set PLATFORM_STORAGE_CLASS=rook-ceph-block on the backend.
+    New app PVCs use rook-ceph-block; existing local-path PVCs are NOT auto-migrated.
+    Object storage credentials: secret {{ .Values.platform.credentialsSecretName }} in {{ .Values.namespace }}.
+{{- end }}