Leave a module out of a send when the store lacks its image, and say it (issue 1742)

cmd/mesh-controller/watchdogs.go

@@ -61,6 +61,9 @@ type signalFacts struct {
 	// held are the machines with moves of recorded modules waiting for a person's push (S24, novox/hq issue 1732).
 	held    []heldFacts
 	heldErr error
+	// images are the modules left out of a send because the artifact store lacks an image they name (S25, issue 1742).
+	images    []imageFacts
+	imagesErr error
 	// refusedSends are the sends a machine refused within the hour for the generation they were composed
 	// from, each naming its sender (S20, novox/hq issue 234).
 	refusedSends    []inventory.Send
@@ -361,6 +364,7 @@ func (w *watchdogs) gather(ctx context.Context) *signalFacts {
 	}
 	f.failed, f.failedErr = gatherFailedPlans(ctx, inv, now)
 	f.held, f.heldErr = gatherHeldMoves(ctx, inv)
+	f.images, f.imagesErr = gatherMissingImagesHere(ctx, inv)
 	f.loop, f.loopErr = w.gatherLoop()
 	f.asks, f.asksErr = w.gatherAsks(ctx, inv)
 	if open, err := w.keeper.Open(ctx); err != nil {