seatgen -check passes at the join: the catalog client's test imports no bus client

branches_test.go named nats.ErrNoResponders for a call that reached no holder, so the generator's
check refused the contracts module ("a client uses only its seat's contract and mesh-sdk's runtime",
ADR 0625 §3), met twice at join 11. The test now gives the words a runtime passes that refusal on
with, which busretry.Undelivered reads the same way.

Builds: design 47 G A-170 (the regenerated contracts, checked in place)

Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h

modules/mesh-delivery-contracts/go/clients/meshcatalogclient/branches_test.go

@@ -3,6 +3,7 @@ package meshcatalogclient
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"slices"
 	"strings"
@@ -14,7 +15,6 @@ import (
 	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-sdk/sourcebranches"
 	"git.novox.be/novox/mesh-sdk/go/busretry"
 	"git.novox.be/novox/mesh-sdk/go/views"
-	"github.com/nats-io/nats.go"
 )
 
 // fakeWiring is a part's reader: it keeps the views adopted, by `<owner>.<state>`, and says each drop.
@@ -255,7 +255,11 @@ func TestEntriesAreAskedOnceAnsweredOrNotFound(t *testing.T) {
 	if rows := viaConn.Rows(); len(rows) != 1 || rows[0].State != EntryNotFound || rows[0].Detail == "" || len(toldConn) == 0 {
 		t.Fatalf("the holder's answer through a process's call: rows %+v, told %d", rows, len(toldConn))
 	}
-	unreached := NewEntries(func(string, any) (json.RawMessage, error) { return nil, nats.ErrNoResponders })
+	// A call that reached no holder, in the words a runtime passes the bus's refusal on with (busretry.Undelivered): a client's
+	// test imports only its seat's contract and mesh-sdk's runtime (ADR 0625 §3), never the bus's client.
+	unreached := NewEntries(func(string, any) (json.RawMessage, error) {
+		return nil, errors.New("nats: no responders available for request")
+	})
 	unreached.Changed = func(r EntryRow) { t.Errorf("a call that reached no holder told %+v", r) }
 	if err := unreached.Again(ctx, "src2:x"); err == nil {
 		t.Fatal("again of an entry never needed answers no error")