refactor(layout): improved layout of the upload ui 改进上传界面布局

[normal-coder]

What has been done / 做了什么事情

改进了上传界面布局，将「追加上传」界面放在页面顶部，便于更灵活的操作。
Improved the layout of the upload interface by placing the "Append Upload" interface at the top of the page for more flexible operation.

Why / 为什么这么做

待上传列表存在内容时，「追加上传」界面会置顶出现。
When there is content in the pending upload list, the "Append Upload" screen will appear at the top of the page.

人的使用习惯更多向上拖拽（鼠标/触摸板向前移，手向前伸）
People tend to drag upwards (mouse/touchpad moves forward, hand reaches forward).

当前布局中，窗口过长时「追加上传」基本会置于屏幕下方。操作时需要鼠标/触摸板向下，手往后抽（往往空间操作比向前伸小），导致拖拽使用体验欠佳。 调整后该问题可解决。
In the current layout, when the window is too long, "Append Upload" is basically placed at the bottom of the screen. When operating, you need to move the mouse/touchpad downward and draw your hand backward (often the space for operation is smaller than that for reaching forward), which leads to poor drag-and-drop experience. This problem can be solved after adjustment.