feat(kubevirt): Add PVC and storage class checks to troubleshooting guide

Extend the DataVolume troubleshooting section (Step 3) to include:

- Check underlying PersistentVolumeClaim (PVC) status
  - Verify PVC phase is "Bound"
  - Check storage class name and capacity
  - Common PVC issues and their meanings

- Check StorageClass when PVC is pending
  - Verify storage class exists
  - Ensure provisioner is healthy

This provides more comprehensive guidance for diagnosing storage-related
issues, as PVC problems are often the root cause of DataVolume failures.
The enhanced troubleshooting steps help users identify issues with:
- Storage class availability
- Provisioner health
- Storage capacity
- PVC binding problems

Assisted-By: Claude <noreply@anthropic.com>
Signed-off-by: Lee Yarwood <lyarwood@redhat.com>

Author: lyarwood

pkg/toolsets/kubevirt/vm/troubleshoot/plan.tmpl

@@ -59,6 +59,43 @@ Look for DataVolumes with names starting with `{{.Name}}-`
   - Phase "ImportScheduled" or "ImportInProgress" - Still importing
   - Phase "Failed" - Check `status.conditions` for error details
 
+### Check Underlying PersistentVolumeClaims
+
+DataVolumes create PVCs to provision storage. Check the PVC status:
+
+Use the `resources_list` tool:
+- **apiVersion**: `v1`
+- **kind**: `PersistentVolumeClaim`
+- **namespace**: `{{.Namespace}}`
+
+Look for PVCs with names matching the DataVolume names (typically `{{.Name}}-*`)
+
+Or inspect a specific PVC with `resources_get`:
+- **apiVersion**: `v1`
+- **kind**: `PersistentVolumeClaim`
+- **namespace**: `{{.Namespace}}`
+- **name**: (name from DataVolume or VM volumes)
+
+**What to look for:**
+- `status.phase` - Should be "Bound" when ready
+- `spec.storageClassName` - Verify the storage class exists and is available
+- `status.capacity.storage` - Confirms allocated storage size
+- Common PVC issues:
+  - Phase "Pending" - Storage class not available, insufficient storage, or provisioner issues
+  - Missing PVC - DataVolume creation may have failed
+  - Incorrect size - Check if requested size matches available storage
+
+**Check Storage Class:**
+
+If PVC is stuck in "Pending", verify the storage class exists:
+
+Use the `resources_get` tool:
+- **apiVersion**: `storage.k8s.io/v1`
+- **kind**: `StorageClass`
+- **name**: (from PVC `spec.storageClassName`)
+
+Ensure the storage class provisioner is healthy and has capacity.
+
 ---
 
 ## Step 4: Check virt-launcher Pod