feat: Настройки › Автообновление - clients compare their version with the server's every N and update themselves; the server looks at GitLab every N and, when a newer release is out, offers it to an administrator at login (after the PIN) with «Обновить» and «Отказаться»; the words of a made picture's result are the model's only

cmd/server/main.go

@@ -6,6 +6,7 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"log"
 	"net/http"
@@ -42,6 +43,9 @@ func main() {
 		log.Fatalf("init server: %v", err)
 	}
 
+	// The server updates itself, if told to (Настройки › Автообновление).
+	go srv.RunAutoUpdate(context.Background())
+
 	httpSrv := &http.Server{
 		Addr:    *addr,
 		Handler: srv.Handler(),