G O-10: a send refused at its sent store's cap names the store (issue 1966)

The error of a refused put said only the label, so a reply or event failed at
a full sent store did not say which store was full.

Builds: design 47 G §477, §59, §181

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

go/stateobjects/send.go

@@ -110,7 +110,8 @@ func (s Sender) Send(label string, body []byte) ([]byte, error) {
 	}
 	ref := Ref{Store: s.Store, Object: objectName(label, digestOf(body)), Size: int64(len(body)), Digest: digestOf(body), Form: FormVersion}
 	if err := s.Objects.Put(ref.Object, body); err != nil {
-		return nil, fmt.Errorf("the object for %s: %w", label, err)
+		// A send refused at its store's cap fails loudly, naming the store (design 47 G §477, §59).
+		return nil, fmt.Errorf("the object for %s in the sent store %s: %w", label, s.Store, err)
 	}
 	if s.Log != nil {
 		if err := s.record(ref.Object); err != nil {

go/stateobjects/values_integration_test.go

@@ -56,6 +56,17 @@ func TestStateObjectsWholeAgainstTheBus(t *testing.T) {
 			}
 		}
 	})
+	// G §477: a send past a fixture's cap fails its reply or event, naming the store.
+	t.Run("a send past the sent store's cap names the store", func(t *testing.T) {
+		small, err := js.CreateObjectStore(ctx, jetstream.ObjectStoreConfig{Bucket: "n_sent-objects", Storage: jetstream.MemoryStorage, MaxBytes: 1 << 20})
+		if err != nil {
+			t.Fatal(err)
+		}
+		s := Sender{Objects: BusObjects{Store: small}, Store: "n_sent-objects", Limit: int(nc.MaxPayload())}
+		if _, err := s.Send("reply.list", []byte(`{"text":"`+strings.Repeat("y", 2<<20)+`"}`)); err == nil || !strings.Contains(err.Error(), "n_sent-objects") {
+			t.Fatalf("a send past the cap: %v, want it refused naming n_sent-objects", err)
+		}
+	})
 	t.Run("values of 1x, 10x and 100x the limit", func(t *testing.T) { valueRows(t, OverBus(kv, store, "m_views-objects"), 1, 10, 100) })
 	t.Run("the tools read and drop what a deleted key left", func(t *testing.T) {
 		v := OverBus(kv, store, "m_views-objects")