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_test.go

@@ -314,7 +314,7 @@ func TestANeedNoNotificationAnswersNamesTheMeshMCPServer(t *testing.T) {
 // as a stalled line in state `unannounced` — no delivery exists, so there is nothing to stop, release or close —
 // and the operator's one act is a new commit on its branch, which the forge announces.
 func TestAnUnannouncedPullRequestSaysToPushANewCommit(t *testing.T) {
-	l := stalledLine{ID: "novox/hq@bfe82315f42c", State: "unannounced", For: "11m0s", Bound: "10m0s",
+	l := stalledLine{ID: "novox/hq@bfe82315f42c", Number: 243, State: "unannounced", For: "11m0s", Bound: "10m0s",
 		H2:   "none: the forge never announced it, so there is no delivery to close — the operator's",
 		Says: "novox/hq#243 is open on main, which requires the merge check, and its head has had no merge check"}
 	obs := stalledObservations([]stalledLine{l})
@@ -325,7 +325,8 @@ func TestAnUnannouncedPullRequestSaysToPushANewCommit(t *testing.T) {
 	if strings.Contains(o.Needs, "stop") || strings.Contains(o.Needs, "release") || !strings.Contains(o.Needs, "commit") {
 		t.Fatalf("it says to %q", o.Needs)
 	}
-	if !strings.Contains(o.Headline, "no merge check") || !strings.Contains(o.Explanation, "never") {
+	if !strings.Contains(o.Headline, "no merge check") || !strings.Contains(o.Headline, "#243") ||
+		!strings.Contains(o.Explanation, "never") {
 		t.Fatalf("it reads %q / %q", o.Headline, o.Explanation)
 	}
 }