puppetdb: give each pod a unique command-queue directory

PuppetDB runs as a Deployment (HPA min 2 / max 5) with its vardir
/opt/puppetlabs/server/data/puppetdb backed by a shared RWX cephfs PVC.
All replicas mount the same path, so they share the stockpile/ command
queue and corrupt each other's unprocessed commands.

Mount the shared PVC with subPathExpr: $(POD_NAME) so each pod gets its
own vardir (and thus its own stockpile queue) on the shared volume.

Claude-Session: https://claude.ai/code/session_01JUoARVdmhxKQHyyyp1pxeT

apps/base/puppet/deployment_puppetdb.yaml

@@ -49,6 +49,10 @@ spec:
             - configMapRef:
                 name: puppetdb-config
           env:
+            - name: POD_NAME
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.name
             - name: OPENVOXDB_POSTGRES_PASSWORD
               valueFrom:
                 secretKeyRef:
@@ -88,6 +92,7 @@ spec:
           volumeMounts:
             - mountPath: /opt/puppetlabs/server/data/puppetdb
               name: puppetdb-storage
+              subPathExpr: $(POD_NAME)
             - mountPath: /etc/puppetlabs/puppetdb/conf.d/read-database.conf
               name: puppetdb-read-database-conf
               subPath: read-database.conf
@@ -99,6 +104,11 @@ spec:
             - -c
           args:
             - mkdir -p /opt/puppetlabs/server/data/puppetdb/logs && chown 999:999 /opt/puppetlabs/server/data/puppetdb/logs
+          env:
+            - name: POD_NAME
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.name
           resources:
             limits:
               cpu: 20m
@@ -111,6 +121,7 @@ spec:
           volumeMounts:
             - mountPath: /opt/puppetlabs/server/data/puppetdb
               name: puppetdb-storage
+              subPathExpr: $(POD_NAME)
 
         - name: pgchecker
           image: docker.io/busybox:1.37