Just-in-time help to warn users that they shouldn't do apt upgrade
As per #15768 (comment 153606).
We already have an FAQ about it but we could do better by providing just-in-help when people run
apt upgrade (or any other variant) on the command line. We could display something like this:
Don't use apt upgrade to upgrade your Tails as it might break break the security built in Tails. Only rely on desktop notification and automatic upgrades to keep your Tails up-to-date.
Could we do even more and break
apt upgrade purposefully on top of displaying this message? Or would this break Additional Software as well?
For another reason to implement a wrapper around
apt-get, see #15584.