distribution's manifest test reads the listens with its own struct and checks every mapping's sides for 5100

Claude-Session: https://claude.ai/code/session_01NcbgfFSnn24M3GcqttoU7i

modules/distribution/internal/holder/holder_test.go

@@ -835,6 +835,10 @@ func TestTheHolderOfTheTwoImageSeats(t *testing.T) {
 			Resources []map[string]any  `json:"resources"`
 			Consumes  []string          `json:"consumes"`
 			Packages  map[string]string `json:"packages"`
+			Listens   []struct {
+				Name string `json:"name"`
+				Port int    `json:"port"`
+			} `json:"listens"`
 		}
 		if err := json.Unmarshal(raw, &m); err != nil {
 			t.Fatal(err)
@@ -893,8 +897,15 @@ func TestTheHolderOfTheTwoImageSeats(t *testing.T) {
 		if len(m.Listens) != 1 || m.Listens[0].Port != 5100 {
 			t.Fatalf("listens = %+v, want registry on 5100, where every machine fetches", m.Listens)
 		}
-		if at, mayAssign := m.MachineSide(5100); at != 5100 || mayAssign {
-			t.Errorf("the machine side of 5100 = %d (may assign %v), want 5100 bound by the program, named by no container", at, mayAssign)
+		for _, r := range m.Resources {
+			ports, _ := r["ports"].([]any)
+			for _, p := range ports {
+				for _, side := range strings.Split(fmt.Sprint(p), ":") {
+					if side == "5100" {
+						t.Errorf("%v maps %v: want 5100 bound by the program, named by no container", r["id"], p)
+					}
+				}
+			}
 		}
 		// Running review F2: incoming asks the bus 8 GiB, the most the objects template allows, equal to IncomingCap
 		// (said only where no binding is read); transfers keeps for good, the holder dropping an idle one by its key