feat(file): unify file handling with a new FileSource abstraction for URL and base64 data

relay/channel/aws/adaptor.go

@@ -49,12 +49,14 @@ func (a *Adaptor) ConvertClaudeRequest(c *gin.Context, info *relaycommon.RelayIn
 			for i2, mediaMessage := range content {
 				if mediaMessage.Source != nil {
 					if mediaMessage.Source.Type == "url" {
-						fileData, err := service.GetFileBase64FromUrl(c, mediaMessage.Source.Url, "formatting image for Claude")
+						// 使用统一的文件服务获取图片数据
+						source := types.NewURLFileSource(mediaMessage.Source.Url)
+						base64Data, mimeType, err := service.GetBase64Data(c, source, "formatting image for Claude")
 						if err != nil {
 							return nil, fmt.Errorf("get file base64 from url failed: %s", err.Error())
 						}
-						mediaMessage.Source.MediaType = fileData.MimeType
-						mediaMessage.Source.Data = fileData.Base64Data
+						mediaMessage.Source.MediaType = mimeType
+						mediaMessage.Source.Data = base64Data
 						mediaMessage.Source.Url = ""
 						mediaMessage.Source.Type = "base64"
 						content[i2] = mediaMessage