fix system library dependency

packages/svelte/src/lib/utils/index.ts

@@ -1,4 +1,4 @@
-import { isNodeBase, isEdgeBase } from '@xyflow/system';
+import { isNodeBase, isEdgeBase, type XYPosition } from '@xyflow/system';
 
 import type { Edge, Node } from '$lib/types';
 
@@ -25,3 +25,10 @@ export const isEdge = <EdgeType extends Edge = Edge>(element: unknown): element
 export function toPxString(value: number | undefined): string | undefined {
   return value === undefined ? undefined : `${value}px`;
 }
+
+export const arrowKeyDiffs: Record<string, XYPosition> = {
+  ArrowUp: { x: 0, y: -1 },
+  ArrowDown: { x: 0, y: 1 },
+  ArrowLeft: { x: -1, y: 0 },
+  ArrowRight: { x: 1, y: 0 }
+};