fixed and improved ui

Client/udpstreamer/main.go

@@ -94,6 +94,7 @@ func main() {
 	http.Handle("/", http.FileServer(http.FS(sub)))
 	http.HandleFunc("/ws", hub.HandleWebSocket)
 	http.HandleFunc("/api/zoom", hub.HandleZoom)
+	http.HandleFunc("/api/export", hub.HandleExport)
 	http.HandleFunc("/version", func(w http.ResponseWriter, r *http.Request) {
 		fmt.Fprint(w, buildVersion)
 	})