LocalSend registers an Ayatana item with no ItemIsMenu and no Activate
handler, so its primary click is a silent no-op and the menu offers only
Open and Quit. Share > Receive already opens it, so drop the item the way
Dropbox's is dropped when its dedicated widget owns the surface.
Closes#6838
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>