feat: add multi-network payment support

- Redesign payment UI with a two-step flow (select coin/network → pay)
  - Add wallet address validation in Telegram bot
  - Rename NetworkEthereum constant from "eth" to "ethereum"

src/model/service/pay_service.go

@@ -32,6 +32,7 @@ func GetCheckoutCounterByTradeId(tradeId string) (*response.CheckoutCounterRespo
 		ExpirationTime: orderInfo.CreatedAt.AddMinutes(config.GetOrderExpirationTime()).TimestampMilli(),
 		RedirectUrl:    orderInfo.RedirectUrl,
 		CreatedAt:      orderInfo.CreatedAt.TimestampMilli(),
+		IsSelected:     orderInfo.IsSelected,
 	}
 	return resp, nil
 }