feat: 添加导出图层功能，支持将图层转换为位图图像并下载

src/component/Canvas/CanvasEditor/components/LayersPanel/LayersPanel.vue

@@ -665,7 +665,19 @@ function buildContextMenuItems(layer) {
         hideContextMenu();
       },
     },
-
+    // 栅格化图层
+    {
+      label: "导出图层",
+      icon: "CExport",
+      disabled:
+        layer.isBackground ||
+        layer.isFixed ||
+        !layerManager?.canRasterizeLayer?.(layer.id),
+      action: () => {
+        exportLayerToImage(layer.id);
+        hideContextMenu();
+      },
+    },
     { type: "divider" },
     // 分组操作 - 带子菜单
     {
@@ -1107,6 +1119,25 @@ async function rasterizeLayer(layerId) {
   }
 }
 
+// 导出图层
+async function exportLayerToImage(layerId) {
+  if (!layerManager?.rasterizeLayer) {
+    console.warn("导出图层功能不可用");
+    return;
+  }
+
+  try {
+    const success = await layerManager.exportLayerToImage(layerId);
+    if (success) {
+      console.log(`✅ 成功导出图层: ${layerId}`);
+    } else {
+      console.warn("导出图层失败");
+    }
+  } catch (error) {
+    console.error("导出图层时发生错误:", error);
+  }
+}
+
 // 合并组图层
 async function mergeGroupLayer(groupId) {
   if (!layerManager?.mergeGroupLayers) {