review: address feedback — update navigation tree on cut/paste

When nodes with subgraphs are cut and pasted to a different graph,
reparent their tree entries so the sidebar tree and breadcrumbs
reflect the new hierarchy.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/NodeContextMenu.tsx

@@ -62,6 +62,7 @@ export default function NodeContextMenu({
   const graphsById = useGraphsStore((s) => (s as { graphsById: Map<string, GraphModel> }).graphsById);
   const addTreeNode = useGraphLayersTreeStore(store => store.add);
   const removeTreeNode = useGraphLayersTreeStore(store => store.remove);
+  const moveTreeNode = useGraphLayersTreeStore(store => store.move);
   const setCut = useCutStore(store => store.setCut);
   const clearCut = useCutStore(store => store.clearCut);
 
@@ -165,6 +166,22 @@ export default function NodeContextMenu({
           }
         }
 
+        // Update navigation tree: reparent tree nodes from source graph to target graph.
+        // A tree node belongs to the source graph when its tree parent matches sourceGraphId
+        // (or is a root node when sourceGraphId is 'main').
+        const treeState = useGraphLayersTreeStore.getState();
+        const effectiveSourceParent = cutState.sourceGraphId === 'main' ? undefined : cutState.sourceGraphId ?? undefined;
+        const newTreeParent = graphContextValue.graphId === 'main' ? undefined : graphContextValue.graphId;
+
+        for (const nodeId of cutState.cutNodeIds) {
+          if (treeState.nodesFlatById.has(nodeId)) {
+            const nodeTreeParent = treeState.parentIdByChildId.get(nodeId);
+            if (nodeTreeParent === effectiveSourceParent) {
+              moveTreeNode(nodeId, newTreeParent);
+            }
+          }
+        }
+
         clearCut();
         break;
       }