Enable iSCSI support for Portworx CSI

- Add dm_round_robin kernel module for Pure Storage multipath
- Uncomment and enable /etc/multipath.conf with Pure-specific settings
- Add apply-iscsi-config.sh script for rolling worker node updates

talos/talhelper/apply-iscsi-config.sh

@@ -0,0 +1,69 @@
+#!/bin/bash
+# Apply iSCSI configuration to worker nodes
+# This regenerates configs with the iscsi-tools extension and applies them
+
+set -e
+
+echo "=========================================="
+echo "Talos iSCSI Configuration Update"
+echo "=========================================="
+echo ""
+echo "This will:"
+echo "  1. Generate new Talos configs with iscsi-tools extension"
+echo "  2. Apply configs to each worker node (one at a time)"
+echo "  3. Reboot each node to load iSCSI modules"
+echo "  4. Wait for each node to become Ready before continuing"
+echo ""
+read -p "Proceed? (y/N): " -n 1 -r
+echo
+if [[ ! $REPLY =~ ^[Yy]$ ]]; then
+  echo "Aborted."
+  exit 0
+fi
+
+echo ""
+echo "Step 1: Generating Talos configurations..."
+talhelper genconfig
+
+declare -A WORKERS=(
+  ["jungle-cruise"]="10.1.71.69"
+  ["haunted-mansion"]="10.1.71.70"
+  ["peter-pans-flight"]="10.1.71.71"
+)
+
+for worker in jungle-cruise haunted-mansion peter-pans-flight; do
+  ip="${WORKERS[$worker]}"
+  echo ""
+  echo "=========================================="
+  echo "Updating $worker ($ip)..."
+  echo "=========================================="
+  
+  echo "Applying configuration (will reboot)..."
+  talosctl apply-config --nodes ${ip} \
+    --file clusterconfig/fastpass-${worker}.yaml \
+    --mode=reboot
+  
+  echo "Waiting for $worker to reboot and become Ready..."
+  sleep 30  # Give it time to start rebooting
+  kubectl wait --for=condition=Ready node/${worker} --timeout=10m
+  
+  echo "✓ $worker is back up."
+  
+  if [ "$worker" != "peter-pans-flight" ]; then
+    echo "Sleeping 30s before next node..."
+    sleep 30
+  fi
+done
+
+echo ""
+echo "=========================================="
+echo "✓ All workers updated!"
+echo "=========================================="
+echo ""
+echo "Verifying iSCSI modules on jungle-cruise..."
+kubectl debug node/jungle-cruise -it --image=busybox -- cat /proc/modules | grep -E "iscsi|multipath" || echo "Modules check failed"
+
+echo ""
+echo "Next steps:"
+echo "  1. Verify iSCSI modules loaded on all nodes"
+echo "  2. Proceed with Portworx CSI installation"