pyyu

https://github.com/gildas-lormeau/SingleFileZ saves to local disk everything on web page.

Yes - see https://en.wikipedia.org/wiki/Audrey_Tang

For an opensource screen recorder, try https://github.com/alyssaxuu/screenity

github motivation says "aerc is really hard to configure" - not to me vs the sample config on github page.

Another command line clients written in Rust is meli.delivery

joker.com, inwx.com ,namesilo.com, register4less.com, epag.de, iwantmyname.com, hover.com, Porkbun.com, www.nearlyfreespeech.net

.name domain isn't available in some of these, decide to use inwx.com

There's croc with relatively small binary for all non-mobile platforms: https://schollz.com/software/sending-a-file/