improve image download with blob conversion for cross-origin support

apps/jingrow/frontend/src/views/tools/RemoveBackground.vue

@@ -487,17 +487,29 @@ const handleDownload = async () => {
   if (!resultImage.value) return
 
   try {
+    // 获取图片数据并转换为 Blob，确保跨域图片也能下载
+    const response = await fetch(resultImage.value)
+    if (!response.ok) {
+      throw new Error(`HTTP error! status: ${response.status}`)
+    }
+    
+    const blob = await response.blob()
+    const blobUrl = URL.createObjectURL(blob)
+    
+    // 创建下载链接
     const link = document.createElement('a')
-    link.href = resultImage.value
+    link.href = blobUrl
     link.download = `removed-background-${Date.now()}.png`
-    link.target = '_blank'
     link.style.display = 'none'
+    
     document.body.appendChild(link)
     link.click()
     
-    setTimeout(() => {
+    // 清理：移除 DOM 元素并释放 blob URL
+    requestAnimationFrame(() => {
       document.body.removeChild(link)
-    }, 100)
+      URL.revokeObjectURL(blobUrl)
+    })
 
     message.success(t('Download started'))
   } catch (error: any) {