更新描述文档；

修复了若干错误；

src/components/ImageCanvas.tsx

@@ -1,6 +1,7 @@
 import React, { useRef, useEffect, useState, useCallback } from 'react';
 import { Stage, Layer, Image as KonvaImage, Line } from 'react-konva';
 import type { KonvaEventObject } from 'konva/lib/Node';
+import type { Stage as StageType } from 'konva/lib/Stage';
 import { useAppStore } from '../store/useAppStore';
 import { Button } from './ui/Button';
 import { ZoomIn, ZoomOut, RotateCcw, Download } from 'lucide-react';
@@ -24,7 +25,7 @@ export const ImageCanvas: React.FC = () => {
     showPromptPanel
   } = useAppStore();
 
-  const stageRef = useRef<any>(null);
+  const stageRef = useRef<StageType>(null);
   const [image, setImage] = useState<HTMLImageElement | null>(null);
   const [stageSize, setStageSize] = useState({ width: 800, height: 600 });
   const [isDrawing, setIsDrawing] = useState(false);