Fix properties panel not updating on node property changes

selectedNodes computed didn't depend on renderVersion, so mutations
to node objects via graph.updateNode() weren't triggering reactivity.
Adding void state.renderVersion ensures the computed recomputes
whenever requestRender() is called.

src/stores/editor.ts

@@ -99,6 +99,7 @@ export function createEditorStore() {
   })
 
   const selectedNodes = computed(() => {
+    void state.renderVersion
     const nodes: SceneNode[] = []
     for (const id of state.selectedIds) {
       const n = graph.getNode(id)