What is the simplest way to connect *directly* to a raspberry pi 4 wirelessly so that I can run commands in a terminal, equivalent to SSH'ing to it but without an ethernet cable or an Access Point? The Pi might be in the middle of a field and I will just be around it with a laptop running linux (ubuntu), no routers or any other infrastructure near it. Security is not really a priority so even an un-encrypted channel would be ok if it simplifies things.

I tried `rfcomm` but had multiple issues:

 - `rfcomm` is now [deprecated][1]. This makes me think there's a newer alternative but I haven't found what it is
 - I followed [this guide][2] but on the client (ubuntu laptop) I don't have the serial device that's supposed to be under `/dev/cu.*`
 - For some reason, most guides I find using rfcomm talk about using android as a client so using a special rfcomm client App, not connecting from linux. Not sure why. having a terminal to type commands in a tiny phone screen seems useless to me
 - I would also like to send files via this connection e.g. to deploy the application that I develop for it in my laptop. If it were ssh, I can just scp. But it seems that rfcomm being a serial console is more like a local than a remote terminal

I currently connect to the Pi via SSH but obviously both the pi and the client need to connect to an external Access Point so that won't work for my real application since the connection needs to be direct from laptop to pi

I'm open to Wifi-direct, bluetooth or any other wireless channel as long as the client can run in linux and it gives me access to a terminal in the pi where I can run commands

  [1]: https://stackoverflow.com/a/70516969/1086540
  [2]: https://forums.raspberrypi.com/viewtopic.php?t=144896