message: FrontBuilder + UpHandler: Fn -> FnOnce
diff: @@ -95,10 +95,10 @@ impl Deref for MessageSSE {
  // trait aliases
  trait_set! {
  pub trait FrontBuilderOutput = Future<Output = Frontend> + 'static;
  - pub trait FrontBuilder<FRBO: FrontBuilderOutput> = Fn() -> FRBO + Clone + Send + 'static;
  + pub trait FrontBuilder<FRBO: FrontBuilderOutput> = FnOnce() -> FRBO + Clone + Send + 'static;
  pub trait UpHandlerOutput = Future<Output = ()> + 'static;
  - pub trait UpHandler<UPHO: UpHandlerOutput, UMsg> = Fn(UpMsgRequest<UMsg>) -> UPHO + Clone + Send + 'static;
  + pub trait UpHandler<UPHO: UpHandlerOutput, UMsg> = FnOnce(UpMsgRequest<UMsg>) -> UPHO + Clone + Send + 'static;
  }
  // ------ ------
  @@ -268,7 +268,7 @@ where
  cor_id: parse_cor_id(headers)?,
  auth_token: parse_auth_token(headers)?,
  };
  - up_msg_handler(up_msg_request).await;
  + up_msg_handler.get_ref().clone()(up_msg_request).await;
  Ok(HttpResponse::Ok().finish())
  }
  @@ -436,7 +436,7 @@ where
  {
  HttpResponse::Ok()
  .content_type(ContentType::html())
  - .body(frontend().await.render(shared_data.cache_busting).await)
  + .body(frontend.get_ref().clone()().await.render(shared_data.cache_busting).await)
  }
  // ====== ====== TESTS ====== ======
  