feat: iSCSI, Longhorn disk labels, labctl asahi command, ZIP32 fix

k3s host prep:
- Add iSCSI initiator install+enable (Fedora: iscsi-initiator-utils,
  Ubuntu: open-iscsi) — required by Longhorn
- Add Longhorn disk label to k3s server+agent configs
- Add Longhorn disk annotation operation in post-install hardening

CLI:
- Add `labctl provision asahi` command with interactive install guide
- Change default SSH user from "michal" to "lab" in all commands
- Change admin user in bastion progress callback to "lab"

Asahi provisioning fixes:
- Download installer_data.json locally (installer reads it as file)
- Use REPO_BASE to serve upstream ZIP from bastion (LAN speed)
- Fix ZIP32 vs ZIP64: serve original upstream ZIP unmodified
  (our repackaged ZIP used ZIP64 which breaks Asahi urlcache)
- Add /data/asahi-repo fallback path for k3s container PVC mount
- Deploy script syncs asahi-repo to bastion pod after deployment

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bastion/scripts/deploy.sh

@@ -24,6 +24,21 @@ deploy_bastion() {
     kubectl rollout restart deployment/bastion -n lab-infra
     kubectl rollout status deployment/bastion -n lab-infra --timeout=180s
     echo "✓ Bastion deployed"
+
+    # Sync Asahi rootfs package to bastion pod's persistent volume
+    if [ -d "$PROJECT_DIR/asahi-repo" ] && [ -f "$PROJECT_DIR/asahi-repo/fedora-asahi-lab.zip" ]; then
+        echo ""
+        echo "=== Syncing Asahi rootfs to bastion pod ==="
+        BASTION_POD=$(kubectl get pods -n lab-infra -l app=bastion -o jsonpath='{.items[0].metadata.name}' 2>/dev/null)
+        if [ -n "$BASTION_POD" ]; then
+            kubectl exec -n lab-infra "$BASTION_POD" -- mkdir -p /data/asahi-repo
+            kubectl cp "$PROJECT_DIR/asahi-repo/installer_data.json" "lab-infra/$BASTION_POD:/data/asahi-repo/installer_data.json"
+            kubectl cp "$PROJECT_DIR/asahi-repo/fedora-asahi-lab.zip" "lab-infra/$BASTION_POD:/data/asahi-repo/fedora-asahi-lab.zip"
+            echo "✓ Asahi rootfs synced ($(du -sh "$PROJECT_DIR/asahi-repo/fedora-asahi-lab.zip" | cut -f1))"
+        else
+            echo "WARNING: Could not find bastion pod — Asahi rootfs not synced"
+        fi
+    fi
 }
 
 deploy_labd() {