feat: unify invite flow with referral ref

inc/helpers/aksrt-credits.php

@@ -42,8 +42,8 @@ if (!function_exists('aksrt_credits_label')) {
             'register'     => __('注册赠送', 'aksrt'),
             'signin'       => __('每日签到', 'aksrt'),
             'comment'      => __('发表评论', 'aksrt'),
-            'invite'       => __('邀请奖励', 'aksrt'),
-            'invitee'      => __('被邀请奖励', 'aksrt'),
+            'referral'     => __('推广注册奖励', 'aksrt'),
+            'referral_new_user' => __('推广注册新用户奖励', 'aksrt'),
             'download'     => __('下载消费', 'aksrt'),
             'admin'        => __('管理员调整', 'aksrt'),
             'refund'       => __('退款', 'aksrt'),