I've asked on the discord and it seems that it is gone, but if I am mistaken let me know and I will remove this.
On TF2 Classic there was setting that meant when you disconnected it would remove the downloaded files from a server, in classified that appears to be gone. There is a similar setting that removes temp files and sprays on shutdown but that does not remove server downloaded files.
If that could be added back it would be very useful for me and maybe other users with limited storage space, appreciate all the work on the game.