feat(control): 设备列表视频源离线警告

- models.Device 增加视频源统计字段(内存/UI用)
- registry graph 轮询(30s)顺带解析 input_rtsp 在线/离线数
- 设备列表状态列: 视频源 N/M 离线 红色警告 pill(悬停显示明细)

control/internal/models/device.go

@@ -19,6 +19,10 @@ type Device struct {
     LastSeenMs          int64       `json:"last_seen_ms"`
     Online              bool        `json:"online"`
     Graphs              interface{} `json:"graphs,omitempty"` // 摘要或详情
+    // 视频源状态统计（由 registry graph 轮询更新，仅内存/UI 用）
+    VideoSourceTotal  int `json:"-"`
+    VideoSourceOnline int `json:"-"`
+    VideoSourceDown   int `json:"-"`
 }
 
 type DeviceRegistry struct {

control/internal/service/registry.go

@@ -101,6 +101,8 @@ func (s *RegistryService) startGraphPolling() {
                 if err := json.Unmarshal(data, &graphs); err == nil {
                     s.mu.Lock()
                     dev.Graphs = graphs
+                    total, online, down := parseVideoSourceStats(graphs)
+                    dev.VideoSourceTotal, dev.VideoSourceOnline, dev.VideoSourceDown = total, online, down
                     s.mu.Unlock()
                     s.persistDevice(dev)
                 }
@@ -109,6 +111,44 @@ func (s *RegistryService) startGraphPolling() {
     }
 }
 
+// parseVideoSourceStats 从 /v1/graphs 响应统计 input_rtsp 视频源在线/离线数。
+func parseVideoSourceStats(graphs any) (total, online, down int) {
+    arr, ok := graphs.([]any)
+    if !ok {
+        return 0, 0, 0
+    }
+    for _, g := range arr {
+        gm, ok := g.(map[string]any)
+        if !ok {
+            continue
+        }
+        nodes, ok := gm["nodes"].([]any)
+        if !ok {
+            continue
+        }
+        for _, n := range nodes {
+            nm, ok := n.(map[string]any)
+            if !ok {
+                continue
+            }
+            if typ, _ := nm["type"].(string); typ != "input_rtsp" {
+                continue
+            }
+            total++
+            cm, ok := nm["custom_metrics"].(map[string]any)
+            if !ok {
+                continue
+            }
+            if streaming, _ := cm["streaming"].(bool); streaming {
+                online++
+            } else {
+                down++
+            }
+        }
+    }
+    return total, online, down
+}
+
 func (s *RegistryService) UpdateDevice(dev *models.Device) {
     s.mu.Lock()
     defer s.mu.Unlock()

control/internal/web/ui/templates/devices.html

@@ -96,6 +96,7 @@
                     <span class="pill bad">未知</span>
                   {{end}}
                   {{if .IntegrationStale}}<span class="pill warn">需重新下发</span>{{end}}
+                  {{if gt .Device.VideoSourceDown 0}}<span class="pill bad" title="{{.Device.VideoSourceDown}}/{{.Device.VideoSourceTotal}} 个视频源离线">视频源 {{.Device.VideoSourceDown}}/{{.Device.VideoSourceTotal}} 离线</span>{{end}}
                   {{if gt .TimeDriftSec $.TimeSyncThreshold}}<span class="pill bad">⏱ 偏差{{.TimeDriftSec}}秒</span>{{end}}
                 </div>
               </div>