The old catalog module drops its claim of the seat mesh-catalog and is deprecated; a check refuses a second claimant (ADR 0604 §6, issue 774)

Claude-Session: https://claude.ai/code/session_01JG73KG7AfSdh6FP8VrBqCn

checks/manifests/main_test.go

@@ -5,6 +5,8 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
 )
 
 // The tree's manifests are ones a judge can read, and no module is named twice. A row is a catalogue of its own: a
@@ -48,3 +50,45 @@ func TestEveryManifestDecodesAndNamesOneModule(t *testing.T) {
 		t.Fatalf("the catalogue holds manifests no judge can read:\n%s", strings.Join(real, "\n"))
 	}
 }
+
+// No manifest of this catalogue claims the seat mesh-catalog: the indexer of the delivery holds it, and the module that
+// held it before has dropped its claim (ADR 0604 §6). A row is a tree of its own: a manifest claiming it is named.
+func TestNoManifestClaimsTheSeatMeshCatalog(t *testing.T) {
+	claimants := func(root string) []string {
+		files, err := filepath.Glob(filepath.Join(root, "modules", "*", "module.json"))
+		if err != nil {
+			t.Fatal(err)
+		}
+		var out []string
+		for _, f := range files {
+			raw, err := os.ReadFile(f)
+			if err != nil {
+				t.Fatal(err)
+			}
+			m, err := catalogue.Decode(raw)
+			if err != nil {
+				continue // Problems names it
+			}
+			for _, c := range m.Claims {
+				if c.Name == "mesh-catalog" {
+					out = append(out, m.Module)
+				}
+			}
+		}
+		return out
+	}
+	row := t.TempDir()
+	if err := os.MkdirAll(filepath.Join(row, "modules", "a"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(row, "modules", "a", "module.json"),
+		[]byte(`{"module":"a","version":"1","claims":[{"name":"mesh-catalog","scope":"mesh"}]}`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if got := claimants(row); len(got) != 1 || got[0] != "a" {
+		t.Fatalf("a manifest claiming the seat is named, got %v", got)
+	}
+	if got := claimants(filepath.Join("..", "..")); len(got) != 0 {
+		t.Errorf("the catalogue's manifests %v claim the seat mesh-catalog: the indexer of the delivery holds it", got)
+	}
+}