I know that habit of using messenger app for notes :) Try [matrix] using Element or SchildiChat. It’s e2eencrypted and federated, and even supports markdown formatting in messages. Also some Slack features are included. The only issue for non-techy person might be verifying sessions - just be sure to use the same client on all devices.

If by wirelessly you mean via Wi-Fi network then one convenient option is qrcp. It generates a QR-code right in your terminal, which you can scan with a phone and send/receive files through a web interface on the URL it provides.

If you want to transfer files regularly, there is another option. Almost every distro has Python installed, and the Python has a “built-in” FTP server. You need to just cd into desired directory and run the command python -m pyftpdlib -w. It will open a FTP server with root in this directory. You then can access it through a file manager, like Material Files for example, and send files and folders back and forth. In Material Files you can save the server address for future use.

Wow, this one hell of a monster will take a place of honor among my containers :) Thanks for sharing!

This + package to enable VSCode marketplace. The only VSCode features it lacks afaik are out of the box settings sync and remote container development, which colud be substituted with plugins.

EDIT: also be sure to check out Lapce suggested by Yote.zip - it’s a banger.