message: fix(store): add viewportBox
diff: @@ -147,6 +147,7 @@ export const storeModel: StoreModel = {
  edges: computed((state) => state.elements.filter(isEdge)),
  selectedElements: null,
  selectedNodesBbox: { x: 0, y: 0, width: 0, height: 0 },
  + viewportBox: computed((state) => ({ x: 0, y: 0, width: state.width, height: state.height })),
  d3Zoom: null,
  d3Selection: null,
  