Refactor insert/materialize node schemas.

This was obviously "already broken" wherever it was cut&paste from, but, FYI, I don't usually line-wrap anything shorter than 105 characters.
Specifically, 105 is the current width that these github diff screens will show without awkward side-scrolling.
And then only for a certain optimal zoom level. At tiny font sizes, github frustratingly widens the left and right margins to over-compensate and preserve the need to side-scroll -- makes no sense.