cut @grok prefix before prompting

main.go

@@ -71,6 +71,8 @@ func (a *App) handleMessage(ctx context.Context, msg *tgbotapi.Message) error {
 		return nil
 	}
 
+	question := msg.Text[len("@grok"):]
+
 	select {
 	case a.sema <- struct{}{}:
 	default:
@@ -79,14 +81,24 @@ func (a *App) handleMessage(ctx context.Context, msg *tgbotapi.Message) error {
 	}
 	defer func() { <-a.sema }()
 
-	a.log.Info("message passed all guards", "text", msg.Text)
+	a.log.Info(
+		"message passed all guards",
+		"og_text", msg.Text,
+		"transformed_text", question,
+	)
 
-	response, err := a.proompter.Prompt(ctx, msg.Text)
+	response, err := a.proompter.Prompt(ctx, question)
 	if err != nil {
 		return fmt.Errorf("prompting: %w", err)
 	}
 
-	_, err = a.bot.Send(tgbotapi.NewMessage(chatID, response.Text))
+	_, err = a.bot.Send(tgbotapi.MessageConfig{
+		BaseChat: tgbotapi.BaseChat{
+			ChatID:           chatID,
+			ReplyToMessageID: msg.MessageID,
+		},
+		Text: response.Text,
+	})
 	if err != nil {
 		return fmt.Errorf("responding: %w", err)
 	}