Say the terminal explicitly, only from a login session, and name the unannounced pull request (hq ADR 0272)

- commandEnvironment takes the terminal as a bool instead of reading an
  empty verb as one; every non-terminal line names its verb and is stripped
  of MESH_CLI_TERMINAL, and a test with the mark set in the serving
  environment fails when that strip is taken out.
- On the control-node the operator's account is the terminal only from a
  login session, as the node-engine reads it from the kernel's cgroup; the
  tool runner and the account's user units run as the operator too, and are
  ordinary calls. The request carries `session` (field-name tests on both
  sides).
- A pull request the forge never announced is named with its number in
  the condition's headline (hq issue 347), from the stalled line's
  `number`, which mesh-delivery sends.

cmd/mesh-controller/plain_words.go

@@ -758,11 +758,14 @@ func stalledWords(l stalledLine, o conditions.Observation) (headline, explanatio
 		if o.Resolver == conditions.ResolverOperator {
 			needs = "push a new commit to its branch; the forge announces it and the mesh checks it."
 		}
-		return fmt.Sprintf("A pull request of %s has had no merge check %s", name, long),
-			fmt.Sprintf("A pull request of %s has been open %s on a branch that requires the merge check, and the "+
-				"mesh was never asked to check it: the forge never announced it. It cannot merge until it is checked.",
-				name, long),
-			fmt.Sprintf("The pull request of %s has a merge check now, or is closed", name), needs, nil
+		pull := "A pull request of " + name
+		if l.Number > 0 {
+			pull = fmt.Sprintf("Pull request %s #%d", name, l.Number)
+		}
+		return fmt.Sprintf("%s has had no merge check %s", pull, long),
+			fmt.Sprintf("%s has been open %s on a branch that requires the merge check, and the mesh was never asked "+
+				"to check it: the forge never announced it. It cannot merge until it is checked.", pull, long),
+			fmt.Sprintf("%s has a merge check now, or is closed", pull), needs, nil
 	}
 	held := l.State
 	if held == "" {