disk-load retires a reading only on its module's key, and measures as soon as its watch catches up (review round 1)

A round no longer retires readings missing from the watched set, which may be empty or partial;
a module's readings are retired when its key of mesh-host_data is deleted or names fewer items.
A round refused before the watch caught up runs once it has, not an hour later. disk_round reads
this machine's key alone, as its grant allows.

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

modules/disk-load/cmd/disk-load/data.go

@@ -115,5 +115,7 @@ func (w *Watched) Follow(k *Keeper) error {
 		return nil
 	})
 	w.Ready()
+	// A round refused while the watch caught up runs now, not at the next hour (the delivery's readings within minutes).
+	go k.RoundIfRefused(context.Background())
 	return nil
 }