fix(mostliked): better shutdown

cmd/mostliked/main.go

···
 		for {
 			_, message, err := conn.ReadMessage()
 			if err != nil {
+				log.Printf("ReadJSON error: %v\n", err)
 				stop()
+				break
 			}
 			jetstreamEvents <- message
 		}

pkg/mostliked/handler.go

···
 		eventCount int
 	)
 
+forLoop:
 	for evt := range events {
+		select {
+		case <-ctx.Done():
+			break forLoop
+		default:
+		}
+
 		if !txOpen {
 			dbTx, err = dbCnx.BeginTx(ctx, nil)
 			if err != nil {