Offer no hand start for a walk that is only waiting its turn (issue 529)

A hand start there would skip its group's order; point at it only for a
walk nothing holds, and say why nothing holds it.

cmd/mesh-controller/issue529_test.go

@@ -51,8 +51,26 @@ func TestAWalkWaitingOnADeliveryNotAtItsTurnSaysSo(t *testing.T) {
 	p := waitingWalk(now)
 	waits := walkWaits{p.ID: {{ID: "novox/mesh-sdk@9747f3e1b1ac", State: "published", Walk: p.ID,
 		Says: "not let go yet: novox/mesh-tools@3f0c1a6cec18 (published) carried by it not at its turn"}}}
-	if line := planLineSaid(p, now, pauseView{}, tierAtLeast, nil, waits); !strings.Contains(line, "not at its turn") ||
-		!strings.Contains(line, "novox/mesh-tools@3f0c1a6cec18") {
+	line := planLineSaid(p, now, pauseView{}, tierAtLeast, nil, waits)
+	if !strings.Contains(line, "not at its turn") || !strings.Contains(line, "novox/mesh-tools@3f0c1a6cec18") {
+		t.Fatalf("the line reads %q", line)
+	}
+	// No hand start offered: it would skip the group's order (review of issue 529).
+	if strings.Contains(line, "plans go") {
+		t.Fatalf("a walk not at its turn points at a hand start: %q", line)
+	}
+}
+
+// A walk nothing holds — the nzbgeek case, its merges' deliveries ended as nothing-to-move — is said so, and the hand
+// start is the way on.
+func TestAWalkHeldByNothingSaysWhyAndTheHandStart(t *testing.T) {
+	now := time.Date(2026, 10, 11, 20, 30, 0, 0, time.UTC)
+	p := waitingWalk(now)
+	waits := walkWaits{p.ID: {{ID: "novox/mesh-media-catalog@cdcdcdcd0000", State: "unheld", Walk: p.ID,
+		Says: "held by nothing: its merges' deliveries ended as nothing-to-move (novox/mesh-media-catalog@abababab0000), " +
+			"yet the walk moves nzbgeek, nzbget — nothing gives it its word"}}}
+	line := planLineSaid(p, now, pauseView{}, tierAtLeast, nil, waits)
+	if !strings.Contains(line, "ended as nothing-to-move") || !strings.Contains(line, "plans go "+p.ID) {
 		t.Fatalf("the line reads %q", line)
 	}
 }