Format PullUpdated, and keep the announced base head on a rechecked member

A head checked again through mesh-delivery reached the direct verdict with no
base head, so a head no build judges was answered with no trunk commit and the
merge tool would refuse it (novox/hq ADR 0323).

cmd/mesh-controller/checks_test.go

@@ -278,3 +278,13 @@ func TestADirectVerdictNamesTheTrunkTheForgeAnnounced(t *testing.T) {
 		t.Fatalf("a forge that said no base head gave the trunk %q", c.Trunk)
 	}
 }
+
+// A head checked again through mesh-delivery (`delivery check --members`, a recheck) reaches the same direct verdict:
+// it names the base head the forge last announced, kept on the member, or the merge tool would refuse it for ever.
+func TestARecheckedHeadsDirectVerdictNamesItsTrunk(t *testing.T) {
+	m := orderMember{ID: "novox/mesh-tools-go@1a2b3c4d5e6f", Repository: "novox/mesh-tools-go", Base: "main",
+		Head: "1a2b3c4d5e6f7a8b9c0d", Number: 3, BaseSHA: "7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b"}
+	if c := directVerdict(m.pull(), link.ChangePlan{}); c.Trunk != "7a8b9c0d1e2f" {
+		t.Fatalf("a rechecked head's direct verdict names trunk %q", c.Trunk)
+	}
+}