feat: 优化选区功能，修复部分bug

src/component/Canvas/CanvasEditor/commands/RasterizeLayerCommand.js

@@ -14,6 +14,7 @@ import {
 } from "../utils/helper";
 import { createRasterizedImage } from "../utils/rasterizedImage";
 import { message } from "ant-design-vue";
+import { restoreFabricObject } from "../utils/objectHelper";
 
 /**
  * 栅格化图层命令
@@ -82,7 +83,7 @@ export class RasterizeLayerCommand extends Command {
       this.canvas.renderAll();
 
       // 检查是否有遮罩对象
-      const maskObject = this._getMaskObject();
+      const maskObject = await this._getMaskObject();
 
       // 创建栅格化图像
       const rasterizedImage = await createRasterizedImage({
@@ -392,9 +393,9 @@ export class RasterizeLayerCommand extends Command {
    * @returns {Object|null} 遮罩对象或null
    * @private
    */
-  _getMaskObject() {
+  async _getMaskObject() {
     // 如果图层有clippingMask，获取对应的fabric对象
-    if (this.layer?.clippingMask?.id) {
+    if (this.layer?.clippingMask) {
       const { object: maskObject } = findObjectById(
         this.canvas,
         this.layer.clippingMask.id
@@ -405,6 +406,7 @@ export class RasterizeLayerCommand extends Command {
         );
         return maskObject;
       }
+      return await restoreFabricObject(this.layer.clippingMask);
     }
 
     console.log("📎 未找到遮罩对象");