GitLab

Fixes many issues with maybes.  Some minor typo-scale stuff; some
pretty consequential.  What to do about speciated lookup methods
still has big honking questions on it: returning a maybe there if
you didn't already have data in that format can be *not cheap*.
Figuring out the best DX there is gonna be interesting.

Making progress on how to handle keys, but slow.  Complex keys are...
well, really complex.  So far I've learned several things that *won't*
work, which is fun.  It's looking unlikely that having a KeyAssembler
type at all is actually going to be a good idea.