Employee. But someone will, ideally, accrue significant equity over time and grow into a leadership position as the company expands. We're funded so it's paid at market rate.

I know it sounds silly but as a startup grows, later in the process investors will want you to have a 'co-founder' who could basically take over if the original founder couldn't for any reason. It's de-risking. Probably needs a different title than 'co-founder'.