refactor: reduce deployment to one compose file

cmd/dyndns-web/main.go

@@ -36,7 +36,7 @@ func run(logger *slog.Logger) error {
 	if err != nil {
 		return err
 	}
-	cipher, err := secure.LoadCipher(cfg.MasterKeyFile)
+	cipher, err := secure.LoadOrCreateCipher(cfg.MasterKeyFile)
 	if err != nil {
 		return err
 	}