Issue grants before code, and the bus's machine first (hq issue 249)

A module's new state reached every machine before the permissions to use
it, which came only with a later push. Memberships and buckets now go
before declarations, the machine holding mesh-broker goes first when its
user list must change, and a grant that fails sends nothing and is an
error so the rollout is retried.

cmd/mesh-controller/hold_test.go

@@ -18,8 +18,8 @@ func TestASendRoundGivesItsHoldBackOnEveryWayOut(t *testing.T) {
 	plain := func(context.Context, string) (sendable, error) {
 		return sendable{Resources: []map[string]any{{"id": "x"}}}, nil
 	}
-	failing := func(readyNode, []byte) error { return errors.New("the broker went away") }
-	fine := func(readyNode, []byte) error { return nil }
+	failing := &recordingDelivery{declareErr: errors.New("the broker went away")}
+	fine := &recordingDelivery{}
 
 	for name, round := range map[string]func() error{
 		"a body that cannot be marshalled": func() error {