Fixed transform issue and added reset

src/myfasthtml/assets/core/hierarchical_canvas_graph.js

@@ -675,7 +675,7 @@ function initHierarchicalCanvasGraph(containerId, options = {}) {
 
   function saveViewState() {
     postEvent('_internal_update_state', {
-      transform: transform,
+      transform: JSON.stringify(transform),  // Serialize to JSON string for server
       layout_mode: layoutMode
     });
   }