Comment # 7 on bug 1088564 from Neil Rickert

It seems that the recommended KDE way of doing this is with a suitable script
in
 $HOME/.config/plasma-workspace/env

I've tested that with something like:

#### ksshagt.sh ###
if [ -z "$SSH_AUTH_SOCK" ] ; then
        eval `ssh-agent -s`
fi
####

The "if" test is needed, in case the KDE login is with X11, where there is
already ssh-agent being started and we won't want to start a second one.  And
it is recommended that a shutdown script also be used to terminate ssh-agent on
logout.

This seems to be working fine, and is probably better than using the standard
shell startup script.