新增 auto-check 工具：网段扫描+SSH登录+压力测试永久循环工作流

- pkg/discovery: TCP端口探测存活主机，ARP表解析MAC作为设备唯一标识
- pkg/sshclient: SSH连接(密码/密钥认证)与远程命令执行
- pkg/stress: stress-ng/stressapptest 压测(cpu/memory/disk/memnative/full)+温度与dmesg监控
- pkg/report: 检测报告生成(文本/JSON)
- pkg/workflow: 永久循环工作流(间隔可配)，MAC唯一标识设备，增量测试+状态变化打印
- pkg/config: YAML分类配置(scan/ssh/stress/report/workflow)
- cmd: cobra入口，仅 --config 指定配置文件

auto-check/pkg/sshclient/sshclient.go

@@ -0,0 +1,93 @@
+package sshclient
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"golang.org/x/crypto/ssh"
+)
+
+// Client SSH 客户端封装
+type Client struct {
+	User     string
+	Password string
+	KeyFile  string
+	Port     int
+	Timeout  time.Duration
+}
+
+// NewClient 创建 SSH 客户端
+func NewClient(user, password, keyFile string, port int, timeout time.Duration) *Client {
+	return &Client{
+		User:     user,
+		Password: password,
+		KeyFile:  keyFile,
+		Port:     port,
+		Timeout:  timeout,
+	}
+}
+
+// Connect 尝试 SSH 连接，返回 SSH client
+func (c *Client) Connect(ip string) (*ssh.Client, error) {
+	config, err := c.buildConfig()
+	if err != nil {
+		return nil, fmt.Errorf("SSH 配置构建失败: %w", err)
+	}
+
+	addr := fmt.Sprintf("%s:%d", ip, c.Port)
+	client, err := ssh.Dial("tcp", addr, config)
+	if err != nil {
+		return nil, fmt.Errorf("SSH 连接 %s 失败: %w", addr, err)
+	}
+	return client, nil
+}
+
+// RunCommand 在远程主机执行命令，返回输出
+func (c *Client) RunCommand(client *ssh.Client, command string) (string, error) {
+	session, err := client.NewSession()
+	if err != nil {
+		return "", fmt.Errorf("创建会话失败: %w", err)
+	}
+	defer session.Close()
+
+	out, err := session.CombinedOutput(command)
+	if err != nil {
+		return string(out), fmt.Errorf("命令执行失败: %w, 输出: %s", err, string(out))
+	}
+	return string(out), nil
+}
+
+// buildConfig 构建 SSH 认证配置
+func (c *Client) buildConfig() (*ssh.ClientConfig, error) {
+	var authMethods []ssh.AuthMethod
+
+	// 密码认证
+	if c.Password != "" {
+		authMethods = append(authMethods, ssh.Password(c.Password))
+	}
+
+	// 密钥认证
+	if c.KeyFile != "" {
+		key, err := os.ReadFile(c.KeyFile)
+		if err != nil {
+			return nil, fmt.Errorf("读取密钥文件失败: %w", err)
+		}
+		signer, err := ssh.ParsePrivateKey(key)
+		if err != nil {
+			return nil, fmt.Errorf("解析私钥失败: %w", err)
+		}
+		authMethods = append(authMethods, ssh.PublicKeys(signer))
+	}
+
+	if len(authMethods) == 0 {
+		return nil, fmt.Errorf("未提供认证方式（密码或密钥）")
+	}
+
+	return &ssh.ClientConfig{
+		User:            c.User,
+		Auth:            authMethods,
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+		Timeout:         c.Timeout,
+	}, nil
+}