Polish CLI help behavior

tests/test_cli.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)
+# shellcheck source=tests/lib/assert.sh
+source "${ROOT_DIR}/tests/lib/assert.sh"
+
+help_output=$("${ROOT_DIR}/iptables-forward.sh" --help)
+assert_contains "${help_output}" '--batch add <proto> <listen_port> <target_ip> <target_port> <ipver> [desc]' 'main script help should describe batch add'
+
+install_help=$("${ROOT_DIR}/install.sh" --help)
+assert_contains "${install_help}" '仅创建符号链接，不复制源码。' 'install help should explain symlink behavior'
+
+pass 'test_cli.sh'