node editor: push/pop imgui ID scopes when rendering nodes

This is a really bad, undefined-behavior hack.
we should hash or something?
or just use the index in the render ordering[1]

[1]: topological ordering of the render graph

src/gui/node_editor.h

@@ -122,6 +122,9 @@ public:
             for (const auto &node : nodeList) {
                 bool visible = viewportRect.intersects(node.bbox);
                 if (visible) {
+                    // TODO: this is garbage
+                    ImGui::PushID((void *)&node);
+
                     // -- Draw the node boxes
                     draw_list->ChannelsSetCurrent(0); // Switch to the background layer
 
@@ -137,6 +140,7 @@ public:
 
                     //     draw_list->AddCircleFilled(offset + position, 4.0f, ImColor(150, 150, 150, 150));
                     // }
+                    ImGui::PopID();
                 }
             }