Tell the operator when the answer to a plan's ask is refused (issue 1316, ADR 0449)

cmd/mesh-controller/asker_wire.go

@@ -174,6 +174,22 @@ func callAction(conn *nats.Conn) func(ctx context.Context, a conditions.Action,
 	}
 }
 
+// tellThrough tells the operator one plain notice through the operator channel's `tell`, over the controller's own
+// connection and grant (novox/hq ADR 0380); a holder's refusal is an error naming it.
+func tellThrough(conn *nats.Conn) func(ctx context.Context, headline string, lines []string) error {
+	return func(ctx context.Context, headline string, lines []string) error {
+		answer, err := link.AskMeshSeatTool(ctx, conn, "operator-channel", "tell",
+			map[string]any{"headline": headline, "lines": lines}, tellWithin)
+		if err != nil {
+			return err
+		}
+		if answer.Error != "" {
+			return fmt.Errorf("operator-channel.tell refused: %s", answer.Error)
+		}
+		return nil
+	}
+}
+
 // routerRecordOf reads the router's record of one of the controller's asks, under its name, and answers
 // how it ended when it did: the bucket is the one the asks seat's declarer names as its records.
 func routerRecordOf(conn *nats.Conn, inv *inventory.Inventory) func(ctx context.Context, id string) (*asks.Warrant, error) {
@@ -576,6 +592,7 @@ func servingAsker(open *stores, conn *nats.Conn, js jetstream.JetStream, keeper
 			_, err := link.RecordHandAct(ctx, conn, act)
 			return err
 		},
+		tell:         tellThrough(conn),
 		routerRecord: routerRecordOf(conn, open.inventory),
 		routerHere:   routerHereIn(open.inventory),
 		grantHeld:    grantHeldIn(open, conn),