Fix demo artwork

Author: adamgerhant

editor/src/messages/portfolio/portfolio_message_handler.rs

@@ -525,6 +525,13 @@ impl MessageHandler<PortfolioMessage, PortfolioMessageData<'_>> for PortfolioMes
 							.network_interface
 							.set_input(&InputConnector::node(NodeId(0), 1), NodeInput::value(TaggedValue::String(label), false), &[*node_id]);
 					}
+
+					// Upgrade construct layer implementation from https://github.com/GraphiteEditor/Graphite/pull/1946
+					if reference == "Merge" {
+						let node_definition = crate::messages::portfolio::document::node_graph::document_node_definitions::resolve_document_node_type(reference).unwrap();
+						let new_merge_node = node_definition.default_node_template();
+						document.network_interface.replace_implementation(node_id, &[], new_merge_node.document_node.implementation)
+					}
 				}
 
 				// TODO: Eventually remove this (probably starting late 2024)