Frame initial canvas loading around direct members

src/components/canvas/headless-graph-canvas.tsx

@@ -55,7 +55,14 @@ function CanvasView({ engine, board, viewId, renderers,fitLoading=true }: { engi
   if (liveView) lastView.current = liveView;
   const view = liveView ?? lastView.current!, flow = useReactFlow<ProjectionNode>();
   const canCreate=!loading||loading.version>=4&&engine.editor.getQueries(root.document).coverage.completeCanvasIds.includes(view.canvasId);
-  useEffect(()=>{if(!needsLoadingFit.current||!flow.viewportInitialized||!root.document.elements.size)return;needsLoadingFit.current=false;void flow.fitView({padding:.2,maxZoom:1});},[flow,root.document]);
+  useEffect(()=>{
+    if(!needsLoadingFit.current||!flow.viewportInitialized||!root.document.canvases.has(view.canvasId))return;
+    // Expanded descendants can extend far beyond their partition entry. Initial
+    // framing belongs to the direct members of this canvas.
+    const nodes=engine.editor.getQueries(root.document).members(view.canvasId).filter(id=>root.document.elements.get(id)?.structure==='node').map(id=>({id}));
+    if(!nodes.length)return;
+    needsLoadingFit.current=false;void flow.fitView({nodes,padding:.2,maxZoom:1});
+  },[engine,flow,root.document,view.canvasId]);
   const preparingCopy = [...(root.runtime.imports?.values() ?? [])].some(job => job.status === 'preparing' && job.source?.targetCanvasId === view.canvasId);
   const [editorFocused, setEditorFocused] = useState(false), focusEpoch = useRef(0);
   useEffect(() => { focusEpoch.current++; setEditorFocused(false); return () => { focusEpoch.current++; }; }, [engine,viewId]);