Empty folder message remains during file operation when the folder is no longer empty (contains visible file items)

### What Happened?

Started copy files into an empty folder that was being viewed. File items were displayed in the view but the empty folder message remained underneath until the operation ended.

### Steps to Reproduce

1. View an empty folder on a slow device
2. Copy sufficient files into it for the operation to last some time
3. Observe file items added to folder but message remains until operation ends.

### Expected Behavior

The message should be removed as soon as file items are visible.

### OS Version

8.x (Circe)

### OS Architecture

amd64 (on most hardwares)

### Session Type

Secure Session (Wayland, This is the default)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell

```

### Hardware Info

_No response_

Start by reproducing the issue in an empty folder while copying files on a slow device, then trace the folder view's empty-state handling. Done means the empty-folder message disappears as soon as visible file items appear, rather than waiting for the operation to finish.

Written by the indexing model from the issue text.