fix: alarmChannelSource统一处理通道后缀，CSV和列表共用一个映射

internal/web/ui.go

@@ -595,6 +595,7 @@ func NewUI(discovery *service.DiscoveryService, registry *service.RegistryServic
                 return ""
             }
         },
+        "alarmChannelSource": alarmChannelSource,
         "statusLabel": func(v string) string {
             switch strings.TrimSpace(v) {
             case "unacknowledged":
@@ -2734,13 +2735,26 @@ func (u *UI) apiAlarmExport(w http.ResponseWriter, r *http.Request) {
     }
     records := u.alarmCollector.ExportFiltered(from, to, deviceID, ruleType)
 
-    // Lookup device info for names and IPs
+    // Device name/IP lookup
     deviceMap := map[string]*models.Device{}
     for _, d := range u.registry.GetDevices() {
         if d != nil {
             deviceMap[d.DeviceID] = d
         }
     }
+    // Channel→source lookup (channel = recognition unit name)
+    channelSources := map[string]string{}
+    if u.preview != nil {
+        if assignments, _ := u.preview.ListDeviceAssignments(); len(assignments) > 0 {
+            for _, a := range assignments {
+                for _, ref := range a.RecognitionUnits {
+                    if unit, err := u.preview.GetRecognitionUnit(ref); err == nil && unit != nil && unit.VideoSourceRef != "" {
+                        channelSources[unit.Name] = unit.VideoSourceRef
+                    }
+                }
+            }
+        }
+    }
 
     w.Header().Set("Content-Type", "text/csv; charset=utf-8")
     w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="alarms_%s_%s.csv"`, from, to))
@@ -2750,27 +2764,11 @@ func (u *UI) apiAlarmExport(w http.ResponseWriter, r *http.Request) {
     for _, a := range records {
         devName := a.DeviceID
         devIP := ""
-        sourceName := a.Channel
         if dev, ok := deviceMap[a.DeviceID]; ok {
             devName = dev.DisplayName()
             devIP = dev.IP
         }
-        // Resolve channel to video source name
-        if u.preview != nil {
-            if assignment, err := u.preview.GetDeviceAssignment(a.DeviceID); err == nil && assignment != nil {
-                for _, ref := range assignment.RecognitionUnits {
-                    if unit, err := u.preview.GetRecognitionUnit(ref); err == nil && unit != nil {
-                        if unit.Name == a.Channel && unit.VideoSourceRef != "" {
-                            sourceName = unit.VideoSourceRef
-                            break
-                        }
-                    }
-                }
-            }
-        }
-        if sourceName == "" {
-            sourceName = a.Channel
-        }
+        sourceName := alarmChannelSource(a.Channel, channelSources)
         fmt.Fprintf(w, "%s,%s,%s,%s,%s,%s,%s\n",
             escapeCSV(formatAlarmTime(a.Timestamp)), escapeCSV(devName), escapeCSV(devIP), escapeCSV(sourceName),
             escapeCSV(alarmRuleLabel(a.RuleName)), escapeCSV(a.ObjectLabel),
@@ -2817,6 +2815,22 @@ func alarmStatusLabel(v string) string {
     }
 }
 
+// alarmChannelSource resolves an alarm channel (e.g. "cam1_alarm_violation") to its video source name.
+// The channel format is {instanceName}_alarm_{type}, where instanceName matches the recognition unit.
+func alarmChannelSource(channel string, sources map[string]string) string {
+    // Try exact match first
+    if src, ok := sources[channel]; ok {
+        return src
+    }
+    // Strip suffix: cam1_alarm_violation → cam1
+    if idx := strings.LastIndex(channel, "_alarm_"); idx > 0 {
+        if src, ok := sources[channel[:idx]]; ok {
+            return src
+        }
+    }
+    return channel
+}
+
 func formatAlarmTime(t string) string {
     // 2026-07-22T13:03:20+08:00 → 2026-07-22 13:03:20
     s := strings.TrimSpace(t)

internal/web/ui/templates/alarms.html

@@ -62,7 +62,7 @@
             <a href="/devices/{{.DeviceID}}">{{index $.AlarmDeviceNames .DeviceID}}</a>
             <div class="muted small mono">{{index $.AlarmDeviceIPs .DeviceID}}</div>
           </td>
-          <td>{{if index $.AlarmChannelSources .Channel}}{{index $.AlarmChannelSources .Channel}}{{else}}{{.Channel}}{{end}}</td>
+          <td>{{alarmChannelSource .Channel $.AlarmChannelSources}}</td>
           <td>
             <span class="pill warn">{{ruleLabel .RuleName}}</span>
           </td>