fix: 判断 conn 是否存在，防止 NOP

router/handler/onvif/subscription.go

@@ -14,7 +14,16 @@ func CreateEventSubscription(c *gin.Context) {
 	xaddr := c.Param("xaddr")
 	callbackURL := event.AttributedURIType(fmt.Sprintf("%s/onvif/subscriptions/%s/callback", config.Conf.App.URL, xaddr))
 	log.Printf("CreateEventSubscription callback URL: %s", callbackURL)
-	result, err := conns[xaddr].SubscribeEvents(callbackURL, "PT60S")
+
+	conn := conns[xaddr]
+	if conn == nil {
+		c.JSON(http.StatusNotFound, gin.H{
+			"message": "Connection not found",
+		})
+		return
+	}
+
+	result, err := conn.SubscribeEvents(callbackURL, "PT60S")
 	if err != nil {
 		c.JSON(http.StatusServiceUnavailable, gin.H{
 			"message": err.Error(),