A swarm has one store, so running it is a fact about this machine and
belongs beside the other deploy.* toggles rather than in the namespace
every host agrees on. Attrset with an enable, not a bare bool, so a
second deployment decision has somewhere to go.
Asserted from swarm.enableRequiredServices alongside the other
once-per-swarm services, and asserted as a mkDefault -- which is what
keeps *where* the store runs a separate question from *that* it runs.
Set it directly to put the store on a host of its own; a hive that does
not run it is a client either way, reaching it by name.
Two descriptions in the file still narrated the old swarm.* layout as
something that used to be true, and the queue's claimed it belongs on
the shared-services host. Both now say what holds.
a5091c58c0