Judge a pull request's head merged into its trunk, and name the trunk commit

A check judged the head alone, so two pull requests that each passed could
break the trunk together (node-engine #66 on 2026-10-09), and a recheck after
the trunk moved judged the same head again. The build seat now merges the head
into the trunk's head in its own clone, never pushed, fails a head that does not
merge cleanly naming the files, and the verdict names the head, the trunk
commit and the commits read beside it, for the forge and mesh-delivery to weigh
against the trunk's next move (novox/hq ADR 0323, issue 341).

cmd/mesh-controller/checks_test.go

@@ -210,3 +210,53 @@ func TestABuildOffTheTrunkIsNeverPublished(t *testing.T) {
 		t.Errorf("a build seat that said nothing was refused: %v", err)
 	}
 }
+
+// **A verdict names the trunk commit it judged** (novox/hq ADR 0323 §3, issue 341): the controller's `checked`
+// carries the head and the trunk commit the build seat merged it into, the commits of the repositories read beside
+// it, how long it took, and the kept delivery plan records the trunk commit with its other inputs. A group's
+// composed check names, per member, the trunk commit that head was merged into (§6).
+func TestAVerdictNamesTheTrunkCommitItJudged(t *testing.T) {
+	plan := &link.ChangePlan{Repository: "novox/mesh-host", Base: "main", Head: "dfb1415aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+		Summary: "builds mesh-host"}
+	asked := &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Number: 66, Base: "main", Plan: plan}
+	c := checkedOf(link.BuildResult{ID: "b", Ref: "dfb1415aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", Checked: asked,
+		Check: &link.CheckOutcome{Verdict: "pass", Took: "4m12s", Head: "dfb1415aaaaa", Trunk: "d28ca95bbbbb",
+			Gate: &link.CheckLayer{Verdict: "pass"}, RepoCheck: &link.CheckLayer{Verdict: "pass"},
+			Beside: map[string]string{"mesh-catalog": "0123456789ab", "mesh-lab": "ba9876543210"}}})
+	if c.Trunk != "d28ca95bbbbb" || c.Commit != "dfb1415aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" {
+		t.Fatalf("the verdict names head %s and trunk %q", c.Commit, c.Trunk)
+	}
+	if c.Beside["mesh-catalog"] != "0123456789ab" || c.Beside["mesh-lab"] != "ba9876543210" {
+		t.Fatalf("the verdict names the repositories read beside it as %v", c.Beside)
+	}
+	if c.Took != "4m12s" {
+		t.Fatalf("the verdict says it took %q", c.Took)
+	}
+	if c.Plan == nil || c.Plan.Trunk != "d28ca95bbbbb" || c.Plan.Head != plan.Head {
+		t.Fatalf("the kept plan records %+v", c.Plan)
+	}
+	if plan.Trunk != "" {
+		t.Fatal("the plan the controller asked with was changed: the verdict's is a copy")
+	}
+
+	group := &link.CheckRequest{Owner: "novox", Repo: "mesh-controller", Number: 7, Base: "main", Group: "feat/x",
+		Members: []link.GroupMember{{Owner: "novox", Repo: "mesh-host", Number: 8, Ref: "cccccccccccc0000", Base: "main"}}}
+	c = checkedOf(link.BuildResult{ID: "g", Ref: "aaaaaaaaaaaa0000", Checked: group, Check: &link.CheckOutcome{
+		Verdict: "pass", Head: "aaaaaaaaaaaa", Trunk: "111111111111", Gate: &link.CheckLayer{Verdict: "pass"},
+		Members: []link.CheckedMember{{Owner: "novox", Repo: "mesh-host", Commit: "cccccccccccc", Trunk: "222222222222"}}}})
+	if len(c.Members) != 2 || c.Members[0].Trunk != "111111111111" || c.Members[1].Trunk != "222222222222" ||
+		c.Members[1].Commit != "cccccccccccc0000" {
+		t.Fatalf("the composed check names its members %+v", c.Members)
+	}
+}
+
+// **The merge made for a check is never registered** (novox/hq ADR 0323 §2): a build of it — a commit on no branch
+// of the forge — is refused, naming the trunk. The rule of ADR 0238 §1 stands unchanged; this holds it for the
+// merge commit a check makes.
+func TestABuildOfACheckMergeIsRefusedNamingTheTrunk(t *testing.T) {
+	merge := link.BuildResult{ID: "b", Commit: "4b5c6d7e8f90aabbccddeeff0011223344556677", Trunk: "main"}
+	err := publishable(merge, "")
+	if !errors.Is(err, errOffTheTrunk) || !strings.Contains(err.Error(), "not on main") {
+		t.Fatalf("a build of a check's merge was answered %v", err)
+	}
+}