Remove dedicated DB devices from Rook-Ceph OSD configuration

Remove metadataDevice (sdb) from all 4 nodes in cluster-values.yaml
since the SATA SSDs are slower than the NVMe data drives. Add temporary
Kyverno mutate policy to protect existing OSD deployments when the
operator is re-enabled - replaces expand-bluefs with a no-op and adds
conditional block.db symlink creation based on BlueStore label detection.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

infrastructure/rook-ceph/cluster-values.yaml

@@ -120,7 +120,6 @@ cephClusterSpec:
         memory: "50Mi"
 
   # Storage configuration - explicit nodes with passthrough NVMe
-  # sdb = dedicated 60GB WAL/DB device per node
   storage:
     useAllNodes: false
     useAllDevices: false
@@ -128,23 +127,15 @@ cephClusterSpec:
       - name: "talos-cp-01"
         devices:
           - name: "nvme0n1"
-        config:
-          metadataDevice: "sdb"
       - name: "talos-cp-02"
         devices:
           - name: "nvme0n1"
-        config:
-          metadataDevice: "sdb"
       - name: "talos-cp-03"
         devices:
           - name: "nvme0n1"
-        config:
-          metadataDevice: "sdb"
       - name: "talos-cp-04"
         devices:
           - name: "nvme0n1"
-        config:
-          metadataDevice: "sdb"
     config:
       osdsPerDevice: "1"