/**
     * Detects card type based on card serial from configure table
     * @param string $cardSerial Card serial number
     * @return string Card type (master, trainer, lifetime, or standard)
     */
    public function detectCardType($cardSerial)
    {
        // Check if card is in master list
        $masterIds = $this->__configDB->getConfigValue('locker_master_ids');
        if ($masterIds) {
            $masterList = array_map('trim', explode(',', $masterIds));
            if (in_array($cardSerial, $masterList)) {
                return 'master';
            }
        }

        // Check if card is in trainer list
        $trainerIds = $this->__configDB->getConfigValue('locker_trainer_ids');
        if ($trainerIds) {
            $trainerList = array_map('trim', explode(',', $trainerIds));
            if (in_array($cardSerial, $trainerList)) {
                return 'trainer';
            }
        }

        // Check if card is in lifetime list
        $lifetimeIds = $this->__configDB->getConfigValue('locker_lifetime_ids');
        if ($lifetimeIds) {
            $lifetimeList = array_map('trim', explode(',', $lifetimeIds));
            if (in_array($cardSerial, $lifetimeList)) {
                return 'lifetime';
            }
        }

        // Default to standard
        return 'standard';
    }