I had a good laugh. Why does anyone want this? Put Linux on your laptop and nuke the network stack. Done.
Take your standard Linux distro…
Make a new user. Login. Uninstall the apps you don’t want. Uninstall the web browser.
You don’t really even have to set up an autostart script to turn off WiFi for this user, but you can if you want. The user not having a web browser installed should be enough.
That’s it, you’re done.