Keep a walk's withheld modules on its record, name every machine a stopped send reached, and list the stop's store tests (review of #232)

cmd/mesh-controller/delivery.go

@@ -191,7 +191,15 @@ func stopWalkWithout(ctx context.Context, inv *inventory.Inventory, id, by, why
 	if batch {
 		return p, said, stopInBatch(ctx, inv, &p, merges, again, &said, stopped, now)
 	}
-	said.Kept = keptOf(p, movesOf(again))
+	entries, err := inv.Catalogued(ctx)
+	if err != nil {
+		return p, said, err
+	}
+	running := map[string][]string{}
+	for _, e := range entries {
+		running[e.Manifest.Module] = e.On
+	}
+	said.Kept = keptOf(p, movesOf(again), running)
 	stopped(&p)
 	p.Delivery.Kept = said.Kept
 	if len(again) == 0 {
@@ -413,8 +421,10 @@ func movesOf(merges []inventory.BatchedMerge) []string {
 }
 
 // keptOf are the modules a stopped walk sent that no merge walked again moves, and the machines each reached:
-// those keep running the stopped walk's build.
-func keptOf(p inventory.Plan, walkedAgain []string) []inventory.PlanKept {
+// those keep running the stopped walk's build. A module sent to its first machines reached those, and the rest it
+// was sent to after them; one sent with no first machine (its policy sends it to all together, or a later tier is
+// built by it) reached every machine running it.
+func keptOf(p inventory.Plan, walkedAgain []string, running map[string][]string) []inventory.PlanKept {
 	var out []inventory.PlanKept
 	for name, m := range p.Modules {
 		if m == nil || slices.Contains(walkedAgain, name) {
@@ -424,6 +434,9 @@ func keptOf(p inventory.Plan, walkedAgain []string) []inventory.PlanKept {
 		if m.FirstAt != nil || m.SentAt != nil {
 			machines = union(machines, m.First)
 		}
+		if m.SentAt != nil && len(m.First) == 0 {
+			machines = union(machines, running[name])
+		}
 		if m.Gate != nil && m.Gate.Since != nil {
 			machines = union(machines, m.Gate.Machines)
 		}