refactor(discovery): use ping for discovery and fill MAC via SSH

auto-check/pkg/discovery/discover.go

@@ -1,23 +1,18 @@
 package discovery
 
 import (
-	"fmt"
-
 	"auto-check/pkg/model"
 )
 
 // Devices 设备表（IP → 设备），每轮 Discover() 后更新，包级公开
 var Devices = make(map[string]model.Device)
 
-// Discover 扫描并更新包级 Devices map（过滤无 MAC 设备，保留上次状态延续）
+// Discover 扫描并更新包级 Devices map
 func (s *Scanner) Discover() {
 	scanned := s.Scan()
-	Devices = make(map[string]model.Device, len(scanned))
+	devices := make(map[string]model.Device, len(scanned))
 	for _, dev := range scanned {
-		if dev.MAC == "" {
-			fmt.Printf("  [!] %s 无 MAC（ARP 未解析），下轮重试\n", dev.IP)
-			continue
-		}
-		Devices[dev.IP] = dev
+		devices[dev.IP] = dev
 	}
+	Devices = devices
 }