swarm: say "no queue coordinates", never "a hive with no queue"

The swarm always has exactly one queue; a hive can only lack its
address. Reworded every prose site this PR added that stated or
implied the opposite, to name what is actually absent (coordinates,
credential, or address) instead of the queue itself.

Refs #3805

hive-c0re/src/meta.rs

@@ -732,7 +732,7 @@ const FORWARDED_VARS: &[&str] = &[
 const FORWARDED_VAR_OPTIONS: &[(&str, &str)] = &[
     // Read at build time to decide whether the harness unit declares the
     // queue credential at all — see `nix/agent-modules/queue.nix`. An agent
-    // whose option says no queue and whose env says otherwise logs the
+    // whose option says no queue coordinates and whose env says otherwise logs the
     // partial-config error rather than half-connecting, which is the same
     // failure this map's doc describes and the reason both halves are wired.
     ("HIVE_AGENT_NATS_URL", "hyperhive.queue.natsUrl"),