improve scrollbar detection and scroll behavior

src/app_layout.cpp

@@ -822,8 +822,6 @@ void App::initLayout()
 
         brush_update();
         
-        TextureManager::load("data/paper.jpg");
-        
         // hacky thing to make the toolbar buttons not steal events when moving cursor fast
         if (auto* toolbar = layout[main_id]->find<Node>("toolbar"))
             toolbar->m_flood_events = true;