Here's a good breakdown of the discussions over the past 100 years including different types of pacifism. Only absolute pacifism argues for no self defense and no defense of others. There is also this that argues specifically that pacifism doesn't always mean a lack of self defense.
As you note in the next section, the 100 years was only in reference to the time since pacifism as a term was coined and I continued to talk about religious groups that have had similar options for thousands of years.
The Jains are only one example. You should probably talk to some Jains as there is much discussion in that community about this. Not all Jains believe the way you think they do. See here as a start.
If you're not even a pacifist, then maybe defer to them to define it.
Since you're not, I take it you agree with what Ukraine is doing then. Good to know we are on the same page.
And your solution is.... to let the trolley roll over them anyway while feeling morally superior. Unless you have some plan of removing the trolley before January, you are choosing to let it crush them anyway. Choosing to not vote or pull the lever is also a choice that you will have to live with and one that requires moral justification.