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-builder/main.go

@@ -256,7 +256,13 @@ func answer(ctx context.Context, publisher builder.Publisher, on, workspace stri
 		v, err = builder.Check(building, builder.Command, checkSpecOf(request), workspace, registry, forgeFrom(), say)
 		if err == nil {
 			result.Check = &link.CheckOutcome{Verdict: v.Verdict, Summary: v.Summary, Report: v.Report,
-				Took: v.Took.Round(time.Second).String(), Gate: layerOf(v.Gate), RepoCheck: layerOf(v.Repo)}
+				Took: v.Took.Round(time.Second).String(), Gate: layerOf(v.Gate), RepoCheck: layerOf(v.Repo),
+				Head: v.Head, Trunk: v.Trunk, Beside: v.Beside}
+			// What each of a group's heads was judged as (novox/hq ADR 0323 §6).
+			for _, m := range v.Members {
+				result.Check.Members = append(result.Check.Members, link.CheckedMember{Owner: m.Owner, Repo: m.Repo,
+					Commit: m.Head, Trunk: m.Trunk})
+			}
 		}
 	} else if err == nil {
 		// The package-registry credential is a build input, so it is resolved before the clone: a
@@ -354,7 +360,7 @@ func checkSpecOf(request link.BuildRequest) builder.CheckSpec {
 	}
 	for _, m := range c.Members {
 		spec.Group = append(spec.Group, builder.GroupHead{Owner: m.Owner, Repo: m.Repo, Repository: m.Repository,
-			Ref: m.Ref, Paths: m.Paths})
+			Ref: m.Ref, Paths: m.Paths, Base: m.Base})
 	}
 	return spec
 }