help users classify columns

so the de stepper is very cool. like very cool. but i suspect some ppl will need help classifying columns, and there are a number of ways we could potentially help them. some day when an llm is baked right into the site, id love to let it have a first pass at classifying them and just have a user validate its choice. but, in the meantime, maybe we just provide some help txt somewhere? a collapsible section just above that ui? or something on hover? idk.. but text could be something like:

> How do I choose?
> - Am I comparing groups? → Biological factor
> - Does this reflect batch or experimental design? → Technical / blocking factor
> - Should the model adjust for this, but I don’t care about testing it? → Other covariate
> - Is this only for QC or filtering? → QC only