增加pdf，xlsx，docx文件预览功能

yangys

2025-12-03 fdb0ed498f295b50c072c4b3652c08e2d60a747a

 src/views/flow/donelist.vue

@@ -320,6 +320,7 @@
                        label: '文件',
                        width: 200,
                        prop: 'file',
                         showOverflowTooltip:true,
                    },
                ],
            },