Nothing it carried is gone -- the two commits before this put all of it
somewhere the work is already being done.
A retired destination is the one shape #25's storage decision does not
make free. A visibility entry is a map key and an unknown key is
dropped on load; a launch page is a *value*, and an unknown one fails
validation -- which on the load path means the app refuses to start for
whoever had Jobs selected. `RetiredViews` is that list, read by
`ApplyDefaults`, which treats a retired name as a zero value. An
unknown-but-not-retired name still errors, because that is a typo and
saying so is the useful answer.