Need Parts Bin categories

Nobody has claimed this yet.

This is a feature request, but it's so important that I consider its absence to be a bug.

It is already the case that the parts bin is so chaotic as to be of no use in creating a clean system. I cannot in good conscience invite others to try out L.next with our current parts bin. Categories would allow us to designate a few islands of sanity in the chaos, without having to deal with the chaos. At the simplest, just put everything in the "chaos" cateogry, and gradually grow a few sinsible categories for the things that are useful or fun and stable.

For instance if we put one good set of widgets (and nothing else) in one category, then everyone could know that is what should be used, and things would be simpler and better.

Moreover, if we made a second (compatible) set of widgets in another category, then we would finally be able to have a configurable UI, just by changing the category name at load time.
Wouldn't that be cool?

The issue names no files, tests, or entry points. Start by locating the parts bin implementation and its loading or selection behavior, then determine how categories should be represented and chosen. Done would include a usable category mechanism that supports isolating stable widget sets, but the precise scope and acceptance criteria need clarification.

Written by the indexing model from the issue text.