Shortcut to delete files

It would be useful if one could delete files from the inbox or library (maybe also from the rename dialog), e.g. by pressing `d` or `Del`.

Look for the UI handling code for the inbox and library views, likely in modules like UI.hs or similar. Identify keybindings and file deletion logic. The feature requires adding a new keybinding (d or Del) and integrating it with the existing file management functions. Test by running the application and verifying files are deleted from the specified locations.

Rédigé par le modèle d'indexation à partir du texte de l'issue.