Why does a text message amount to contract acceptance? Even if there wasn't a misunderstanding, I wouldn't believe this to be true if you had asked me yesterday.
If I text someone "sell me your tv for $1" and he replies "ok" can I sue him if he doesn't?
I don't know of any backup program that integrates with a file manager. For my use case (plug in an external hard drive and backup stuff to it once a week) FreeFileSync works fine.
rclone
is a popular CLI program to automatically backup your files on a cloud service. With some searching, it seems that it also provides a web GUI and can be used with OneDrive, so I suppose that's worth checking.As for defender services, I have no idea, but from my understanding most people don't use an antivirus on Linux.