Drag & Drop was never implemented, and because the frontend is basically a webbrowser, the default behavior to dropping is changing the url to the dropped file. I will check if I could change this.

I'll see what I can do in my work too; this looks relevant:
https://stackoverflow.com/questions/6756583/prevent-browser-from-loading-a-drag-and-dropped-file?rq=1
The trick will be still allowing drag-n-drop in the files/operations tab when assembling jobs..

This is now in my fork, hopefully it will be merged to the main branch soon.

Works well, doesnt interfere with in-window dragging, and guides new users into what to do.
easytarget-org@4822c19

@cprezzi should we get this merged?