deploy: move the queue toggle

Same shape as the others. Three of the eight references were prose
rather than code: two assertion messages naming the option to an
operator, and a `defaultText` in the authelia module, whose
`oidc.hiveIdentities` derives from whether the queue runs here.

Also corrects a comment in swarm.nix that this commit's own hunk sits
directly beneath. It said `enableRequiredServices` turns on matrix and
authelia "but NOT nats (nats has no mode that enables it)", which stopped
being true when the queue was added to that switch — before this change,
not by it. The reasoning it introduces is still right and still worth
keeping; only the premise had expired.

nix/host-modules/local-defaults.nix

@@ -95,7 +95,7 @@ in
     # ran its first boot on — so they belong to the mode that asserts this
     # box is the whole deployment, not to the options' own `default`.
     #
-    # Deriving them from `swarm.nats.enable` / `deploy.authelia`
+    # Deriving them from `deploy.nats` / `deploy.authelia`
     # inside those defaults is the mixing this file exists to prevent: the
     # option would be describing a deployment shape instead of describing
     # itself, and "what does all-local turn on?" would stop having one