refactoring: graph state

frontend/src/hooks/useGraphStateWithHistory.ts

@@ -1,6 +1,11 @@
 import { useCallback, useRef, useState } from 'react'
 import type { AppNode, AppEdge } from '@/lib/graph/nodeTypes'
 
+/**
+ * In-memory graph state. History is a past/future stack of GraphState snapshots.
+ * setNodes/setEdges push current state to past; setNodesSilent/setEdgesSilent update without history.
+ * setStateImmediate replaces state and clears history (e.g. load example, import).
+ */
 export type GraphState = { nodes: AppNode[]; edges: AppEdge[] }
 
 function cloneState(state: GraphState): GraphState {