价差高频套利
从接入，到有序运行。

sudo systemctl disable --now panda-four.service
sudo rm -f -- /etc/systemd/system/panda-four.service
sudo rm -rf -- /etc/systemd/system/panda-four.service.d
sudo rm -rf -- /opt/pandazhai/four /var/lib/pandazhai/four
sudo systemctl daemon-reload

sudo bash <<'PANDA_CLEAR_LEGACY'
set -euo pipefail
legacy_nodes=(entropy popdex rblighter vanta arcus decibel qfex)

# 先停止全部旧节点；任一服务停止失败则中止，不删除数据。
for node in "${legacy_nodes[@]}"; do
  unit="panda-${node}.service"
  state=$(systemctl show "$unit" --property=LoadState --value)
  if [[ "$state" != "not-found" ]]; then
    systemctl disable --now "$unit"
    if systemctl is-active --quiet "$unit"; then
      echo "旧服务仍在运行，已中止：$unit" >&2
      exit 1
    fi
  fi
done

# 固定名单清除；不匹配或删除 four、管理中心及备份目录。
for node in "${legacy_nodes[@]}"; do
  rm -f -- "/etc/systemd/system/panda-${node}.service"
  rm -rf -- "/etc/systemd/system/panda-${node}.service.d" "/opt/pandazhai/${node}" "/var/lib/pandazhai/${node}"
done
systemctl daemon-reload
echo '七类旧一对一节点已清除；多平台节点与备份目录保留。'
PANDA_CLEAR_LEGACY