重构 auto-check：拆分包架构，精简 workflow 为纯调度循环

各包职责：
- config: 分类 YAML 配置
- model: Device/IP/MAC 公共类型
- discovery: 扫描 + ARP MAC 解析 + Devices 变量
- sshclient: SSH 连接
- stress: stress-ng/stressapptest 压测 + Results 变量
- report: 80mm 热敏模板/sparkline/打印 + Printed 变量
- workflow: 永久循环调度 + Start/Stop

workflow 已精简为 100 行纯编排，所有业务逻辑下沉各包

auto-check/pkg/report/device.go

@@ -0,0 +1,77 @@
+package report
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"auto-check/pkg/config"
+	"auto-check/pkg/model"
+	"auto-check/pkg/stress"
+)
+
+// BuildDeviceReport 由压测结果构建设备报告（MAC 唯一标识）
+func BuildDeviceReport(dev *model.Device, rpt *stress.Report) *Report {
+	b := NewBuilder(ConfigSummary{})
+	b.StartPhase("压力测试")
+	b.AddHost(HostResult{MAC: dev.MAC, IP: dev.IP})
+	for _, res := range rpt.Results {
+		b.AddStressResult(dev.MAC, StressResult{
+			Type:     string(res.Type),
+			Status:   res.Status,
+			Duration: res.Duration.String(),
+			Error:    res.Error,
+			Output:   res.Output,
+		})
+	}
+	b.EndPhase(rpt.Summary())
+	return b.Build()
+}
+
+// SaveDeviceReport 保存设备报告（文件名含 MAC/IP/时间戳）
+func SaveDeviceReport(dev *model.Device, rpt *stress.Report, dir string) error {
+	if dir == "" {
+		dir = "reports"
+	}
+	ts := time.Now().Format("20060102-150405")
+	name := strings.ReplaceAll(dev.MAC, ":", "")
+	path := filepath.Join(dir, fmt.Sprintf("report-%s-%s-%s.txt", name, dev.IP, ts))
+	return BuildDeviceReport(dev, rpt).SaveFile(path, "text")
+}
+
+// PrintDeviceReport 渲染 80mm 模板并送打印机
+func PrintDeviceReport(dev *model.Device, rpt *stress.Report, cfg config.PrintConfig) error {
+	width := cfg.Width
+	if width <= 0 {
+		width = 42
+	}
+
+	text, err := BuildDeviceReport(dev, rpt).Render80mmWithConfig(TemplateConfig{Width: width})
+	if err != nil {
+		return err
+	}
+
+	printer, err := NewPrinter(config.PrintConfig{Enabled: true, Backend: cfg.Backend, Device: cfg.Device, Width: width})
+	if err != nil {
+		return err
+	}
+	defer printer.Close()
+
+	return printer.Print(text)
+}
+
+// SaveAndPrintDeviceReport 保存报告并（启用时）打印，含错误输出（一站式业务入口）
+func SaveAndPrintDeviceReport(dev *model.Device, rpt *stress.Report, dir string, printCfg config.PrintConfig) {
+	if err := SaveDeviceReport(dev, rpt, dir); err != nil {
+		fmt.Printf("  [报告] %s 保存失败: %v\n", dev.IP, err)
+	}
+
+	if printCfg.Enabled {
+		if err := PrintDeviceReport(dev, rpt, printCfg); err != nil {
+			fmt.Printf("  [打印] %s 失败: %v\n", dev.IP, err)
+		} else {
+			fmt.Printf("  [打印] %s 已送出 (%s)\n", dev.IP, printCfg.Backend)
+		}
+	}
+}