Call for discussion: Phase names

[Levi Bard]

> However, by that logic, "public" could be improved to highlight the
> distinguishing property (immutability). Maybe permanent/draft/local?

Continuing that logic, why not just call them "immutable" ?
For one thing, it will short-circuit the billion instances of the
following exchange:
"Hey, what's the difference between public and draft changesets?"
"Public changesets are immutable."

Going farther, what about immutable / mutable / whatever ?