fix: 批处理统一过滤离线设备，时间同步跳过无偏差设备

internal/service/task.go

@@ -431,6 +431,24 @@ func (s *TaskService) executeOnDevice(task *models.Task, did string) {
 
     case "time_sync":
         nowMS := time.Now().UnixMilli()
+        // Check current drift first — skip if already in sync
+        devBody, devCode, devErr := s.agent.Do("GET", dev.IP, dev.AgentPort, "/v1/time", nil)
+        if devErr == nil && devCode == 200 {
+            var tresp struct {
+                UnixMS int64 `json:"unix_ms"`
+            }
+            if json.Unmarshal(devBody, &tresp) == nil {
+                diff := (nowMS - tresp.UnixMS) / 1000
+                if diff < 0 {
+                    diff = -diff
+                }
+                if diff <= 5 {
+                    s.updateDeviceStatus(task.ID, did, models.TaskSuccess, 1.0, "时间已同步")
+                    s.appendAuditLog(task, did, models.TaskSuccess, "")
+                    return
+                }
+            }
+        }
         body, _ := json.Marshal(map[string]int64{"unix_ms": nowMS})
         _, code, err := s.agent.Do("POST", dev.IP, dev.AgentPort, "/v1/time/set", body)
         if err != nil {

internal/web/ui.go

@@ -1737,6 +1737,22 @@ func (u *UI) actionDiscoverySearch(w http.ResponseWriter, r *http.Request) {
     u.render(w, r, "devices", data)
 }
 
+func filterOnlineDeviceIDs(devices []*models.Device, ids []string) []string {
+    online := map[string]bool{}
+    for _, d := range devices {
+        if d != nil && d.Online {
+            online[d.DeviceID] = true
+        }
+    }
+    out := make([]string, 0, len(ids))
+    for _, id := range ids {
+        if online[id] {
+            out = append(out, id)
+        }
+    }
+    return out
+}
+
 func (u *UI) actionDevicesBatchAction(w http.ResponseWriter, r *http.Request) {
     _ = r.ParseForm()
     action := strings.TrimSpace(r.FormValue("action"))
@@ -1746,6 +1762,8 @@ func (u *UI) actionDevicesBatchAction(w http.ResponseWriter, r *http.Request) {
         return
     }
     deviceIDs := filterSelectedDeviceIDs(u.registry.GetDevices(), r.Form["device_id"])
+    // Common filter: remove offline devices for all actions except cleanup_offline
+    deviceIDs = filterOnlineDeviceIDs(u.registry.GetDevices(), deviceIDs)
     if len(deviceIDs) == 0 {
         u.render(w, r, "devices", u.deviceOverviewPageData(r, nil, "请先选择设备"))
         return