Add k8s DaemonSet design for RKE2 nodes (Model A, per-node self-contained)

Design artifact (NOT applied). Per-node pod = host-poller + redis + web sharing
pod localhost; only host-poller privileged with hostPath /dev+/sys. No SAS
poller (no enclosures). MQTT_NODE_ID from spec.nodeName; MQTT creds via VSO
VaultStaticSecret reading secret/home_assistant (mqtt_user/pass -> MQTT_USERNAME/
PASSWORD). nodeSelector jbod-monitor=enabled to pin to pascal/currie/fermi.

k8s/daemonset.yaml

@@ -0,0 +1,104 @@
+# jbod-monitor on RKE2 nodes — per-node self-contained DaemonSet (Model A).
+#
+# Each scheduled node runs one pod = host-poller + redis + web, sharing the
+# pod's localhost (no hostNetwork needed). Only host-poller is privileged and
+# mounts /dev + /sys to read IPMI / SMART / coretemp. web egresses to the MQTT
+# broker and publishes a per-node HA device (MQTT_NODE_ID = spec.nodeName).
+#
+# No SAS poller (these nodes have no SES enclosures). NOTE: without it there is
+# no zfs_map, so host-drive entities won't carry a ZFS pool label.
+#
+# Target nodes are chosen by label — see k8s/README.md (label only
+# pascal/currie/fermi). Apply order: namespace -> VaultStaticSecret -> this.
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: jbod-monitor
+---
+apiVersion: apps/v1
+kind: DaemonSet
+metadata:
+  name: jbod-monitor
+  namespace: jbod-monitor
+  labels:
+    app: jbod-monitor
+spec:
+  selector:
+    matchLabels:
+      app: jbod-monitor
+  template:
+    metadata:
+      labels:
+        app: jbod-monitor
+    spec:
+      # Only nodes explicitly opted in (see README: kubectl label node ...).
+      nodeSelector:
+        jbod-monitor: "enabled"
+      # If the registry needs auth, sync a regcred and uncomment:
+      # imagePullSecrets:
+      #   - name: regcred
+      containers:
+        - name: redis
+          image: redis:7-alpine
+          args: ["redis-server", "--save", "60", "1", "--loglevel", "warning"]
+          volumeMounts:
+            - name: redis-data
+              mountPath: /data
+          resources:
+            requests: {cpu: 25m, memory: 32Mi}
+            limits: {memory: 128Mi}
+
+        - name: host-poller
+          image: docker.adamksmith.xyz/jbod-host-poller:514502e
+          securityContext:
+            privileged: true   # raw /dev access for ipmitool + smartctl
+          env:
+            - {name: TZ, value: "America/Denver"}
+            - {name: REDIS_HOST, value: "127.0.0.1"}
+            - {name: REDIS_PORT, value: "6379"}
+            - {name: HOST_ENV_INTERVAL, value: "60"}
+            - {name: HOST_DRIVE_INTERVAL, value: "300"}
+            - {name: POLL_CONCURRENCY, value: "1"}
+            - {name: POLL_DRIVE_GAP, value: "0.5"}
+            - {name: POLL_STARTUP_JITTER, value: "10"}
+            - {name: POLL_DATA_TTL, value: "900"}
+          volumeMounts:
+            - {name: dev, mountPath: /dev}
+            - {name: sys, mountPath: /sys, readOnly: true}
+            - {name: udev, mountPath: /run/udev, readOnly: true}
+          resources:
+            requests: {cpu: 25m, memory: 64Mi}
+            limits: {memory: 256Mi}
+
+        - name: web
+          image: docker.adamksmith.xyz/jbod-web:1839e9d
+          env:
+            - {name: TZ, value: "America/Denver"}
+            - {name: REDIS_HOST, value: "127.0.0.1"}
+            - {name: REDIS_PORT, value: "6379"}
+            - {name: MQTT_HOST, value: "10.5.30.3"}
+            - {name: MQTT_PORT, value: "1883"}
+            - {name: MQTT_DISCOVERY_PREFIX, value: "homeassistant"}
+            - {name: MQTT_BASE_TOPIC, value: "jbod-monitor"}
+            - {name: MQTT_PUBLISH_INTERVAL, value: "60"}
+            - name: MQTT_NODE_ID
+              valueFrom:
+                fieldRef:
+                  fieldPath: spec.nodeName
+          envFrom:
+            - secretRef:
+                name: jbod-mqtt   # MQTT_USERNAME / MQTT_PASSWORD (see VaultStaticSecret)
+          resources:
+            requests: {cpu: 25m, memory: 64Mi}
+            limits: {memory: 256Mi}
+
+      volumes:
+        - name: redis-data
+          emptyDir: {}
+        - name: dev
+          hostPath: {path: /dev}
+        - name: sys
+          hostPath: {path: /sys}
+        - name: udev
+          hostPath: {path: /run/udev}