Assert the bus's objects on every send, not only at start (hq issue 208)

A module or seat holder assigned after the controller started was sent
its declaration and found nothing to bind: messenger on novox
("consumer novox_messenger not found", 2026-10-06) and every first
build-agent holder (2026-10-03). assertBusObjects ran only in the start
raise; a push ensured a module's consumer only when a bus credential was
minted, which a module carried by the runtime never is.

The send's grant now runs the same derivation (assertOnSend) before the
memberships, on every push, cascade, plan send and rotation. A failure
is said in the send's output and raised as bus.objects.unasserted, which
the next send that asserts everything clears; the send itself goes on,
because the objects are the mesh's and holding every machine back for
one would turn one fault into all. Module consumers are each tried and
every failure named. The start raise stays as it was.

cmd/mesh-controller/push.go

@@ -776,6 +776,13 @@ type overTheBus struct {
 }
 
 func (b overTheBus) grant(ctx context.Context, sending []readyNode) error {
+	// The bus's objects first, which every declaration implies (novox/hq issue 208): said and raised
+	// when they cannot be, and never what holds the send back (assertOnSend).
+	if bus, ok := b.server.Bus().(link.OverNATS); ok {
+		js := broker.OnConn(bus.Conn)
+		js.Note = func(format string, args ...any) { fmt.Printf(b.indent+"  "+format+"\n", args...) }
+		_ = assertOnSend(ctx, b.open.inventory, js, b.indent)
+	}
 	return issueMemberships(ctx, b.open, b.server, sending)
 }