feat: SSH 成功获取系统信息时视为机器在线

在连通性检测逻辑中，当 network ping / ICMP / TCP 三层探测均失败后，
若机器配置了 SSH 凭据，则同步尝试调用 GetSSHInfo 进行 SSH 信息采集：
- 若 SSH 采集成功，则将该机器判定为在线，并保存获取到的系统信息；
- 若 SSH 采集也失败，则保持离线状态，按原逻辑记录离线日志。

此改进可避免以下场景导致的误判：
- 机器禁 ping 或 ICMP 被防火墙拦截；
- SSH 端口未被网络层探测正确识别；
- 只要 SSH 服务正常且能正确登录并获取系统信息，即认为机器处于可用状态。

其他改动：
- 提取 saveSSHResult 辅助函数，统一保存 SSH 采集结果，避免重复代码。
- 同步更新了本地与 Linux 部署二进制文件。

server/services/ping.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"lan-manager/server/db"
+	"lan-manager/server/models"
 	"lan-manager/server/utils"
 	"net"
 	"os"
@@ -146,9 +147,43 @@ type machinePing struct {
 	wasOnline   bool
 }
 
+func saveSSHResult(mid int64, mip string, mport int, result *models.SSHInfoResult) {
+	portsStr := ""
+	if len(result.ListenPorts) > 0 {
+		b, _ := json.Marshal(result.ListenPorts)
+		portsStr = string(b)
+		if len(portsStr) > 2 {
+			portsStr = portsStr[1 : len(portsStr)-1]
+		}
+	}
+	_, dbErr := db.DB.Exec(`UPDATE machines SET cpu_info=?, memory_info=?, disk_info=?, uptime=?, listen_ports=?, ssh_synced_at=CURRENT_TIMESTAMP, updated_at=CURRENT_TIMESTAMP WHERE id=?`,
+		result.RawCPUInfo, result.RawMemoryInfo, result.RawDiskInfo, result.Uptime, portsStr, mid)
+	if dbErr != nil {
+		fmt.Printf("[SSH] auto-fetch db error for %s:%d: %v\n", mip, mport, dbErr)
+	} else {
+		fmt.Printf("[SSH] auto-fetch success for %s:%d\n", mip, mport)
+	}
+}
+
 func handlePingResult(m *machinePing, res PingResult) {
 	online := res.Online
 	reason := res.Reason
+	var sshResult *models.SSHInfoResult
+
+	// 如果网络层检测失败，尝试通过 SSH 获取系统信息来判定在线
+	if !online && m.sshUsername != "" && m.sshPassword != "" {
+		plainPass, decryptErr := utils.Decrypt(m.sshPassword)
+		if decryptErr == nil {
+			result, err := GetSSHInfo(m.ip, m.sshPort, m.sshUsername, plainPass)
+			if err == nil {
+				online = true
+				reason = ""
+				sshResult = result
+				fmt.Printf("[Ping] %s -> network unreachable, but SSH info fetched successfully, treating as online\n", m.ip)
+			}
+		}
+	}
+
 	var onlineInt int
 	if online {
 		onlineInt = 1
@@ -185,6 +220,9 @@ func handlePingResult(m *machinePing, res PingResult) {
 			_, _ = db.DB.Exec(`UPDATE machines SET total_offline_seconds=total_offline_seconds+? WHERE id=?`, duration, m.id)
 		}
 		m.wasOnline = true
+		if sshResult != nil {
+			saveSSHResult(m.id, m.ip, m.sshPort, sshResult)
+		}
 		return
 	}
 
@@ -197,33 +235,23 @@ func handlePingResult(m *machinePing, res PingResult) {
 	}
 
 	if online && m.sshUsername != "" && m.sshPassword != "" {
-		go func(mid int64, mip string, mport int, muser, mpass string) {
-			plainPass, decryptErr := utils.Decrypt(mpass)
-			if decryptErr != nil {
-				fmt.Printf("[SSH] decrypt failed for %s:%d: %v\n", mip, mport, decryptErr)
-				return
-			}
-			result, err := GetSSHInfo(mip, mport, muser, plainPass)
-			if err != nil {
-				fmt.Printf("[SSH] auto-fetch failed for %s:%d: %v\n", mip, mport, err)
-				return
-			}
-			portsStr := ""
-			if len(result.ListenPorts) > 0 {
-				b, _ := json.Marshal(result.ListenPorts)
-				portsStr = string(b)
-				if len(portsStr) > 2 {
-					portsStr = portsStr[1 : len(portsStr)-1]
+		if sshResult != nil {
+			saveSSHResult(m.id, m.ip, m.sshPort, sshResult)
+		} else {
+			go func(mid int64, mip string, mport int, muser, mpass string) {
+				plainPass, decryptErr := utils.Decrypt(mpass)
+				if decryptErr != nil {
+					fmt.Printf("[SSH] decrypt failed for %s:%d: %v\n", mip, mport, decryptErr)
+					return
 				}
-			}
-			_, dbErr := db.DB.Exec(`UPDATE machines SET cpu_info=?, memory_info=?, disk_info=?, uptime=?, listen_ports=?, ssh_synced_at=CURRENT_TIMESTAMP, updated_at=CURRENT_TIMESTAMP WHERE id=?`,
-				result.RawCPUInfo, result.RawMemoryInfo, result.RawDiskInfo, result.Uptime, portsStr, mid)
-			if dbErr != nil {
-				fmt.Printf("[SSH] auto-fetch db error for %s:%d: %v\n", mip, mport, dbErr)
-			} else {
-				fmt.Printf("[SSH] auto-fetch success for %s:%d\n", mip, mport)
-			}
-		}(m.id, m.ip, m.sshPort, m.sshUsername, m.sshPassword)
+				result, err := GetSSHInfo(mip, mport, muser, plainPass)
+				if err != nil {
+					fmt.Printf("[SSH] auto-fetch failed for %s:%d: %v\n", mip, mport, err)
+					return
+				}
+				saveSSHResult(mid, mip, mport, result)
+			}(m.id, m.ip, m.sshPort, m.sshUsername, m.sshPassword)
+		}
 	}
 }