How would you define power harassment in the workplace?

I wouldn't. I would use a pre-existing English expression whose meaning is clear, like "abuse of power" or "workplace bullying".

In two words, senpai, kohai.

Very precisely.

I don't know how it's defined. But I do know that the broader the definition gets, the more attractive robots look.

Nothing special, only to adapt this world. Nowhere to be paradise I know!