Hey, thanks for the kind words!

Yeah sample size calculations for Bayesian inference can be kind of confusing. Here's an R package that does a lot of the calcs for you (scroll to the bottom).

In short, there are two ways to approach the calculation. The first involves calculating the sample size prior to the experiment and the second iteratively updates if stat sig has not been reached. Both are outlined in the paper linked above.

It's surprising there aren't very accessible resources (that I found). Thanks for the question and lmk if have more :)