chore(admin): clarify download points purchase mode copy

Rename residual 积分扣费/按次扣费 labels to 积分购买模式 and note cashier unlock; keep download_credit key for storage.

inc/classes/admin/schema/class-aksrt-admin-schema-permissions.php

@@ -123,8 +123,8 @@ class AKSRT_Admin_Schema_Permissions {
                     'groups'     => [
                         ['key' => 'basic', 'title' => '下载设置', 'fields' => [
                             ['key' => 'download_require_login', 'label' => '下载需要登录', 'type' => 'switch', 'default' => true],
-                            ['key' => 'download_require_credits', 'label' => '下载需要积分', 'type' => 'switch', 'default' => false],
-                            ['key' => 'download_credits_cost', 'label' => '下载所需积分', 'type' => 'number', 'default' => 1, 'min' => 1, 'max' => 100],
+                            ['key' => 'download_require_credits', 'label' => '允许积分购买模式', 'type' => 'switch', 'default' => false, 'help' => '兼容字段；运行时以 cms_features.download_credit 为准。开启表示 pay_modo=积分 可收银台一次购买，不是按次扣费。'],
+                            ['key' => 'download_credits_cost', 'label' => '默认积分价参考', 'type' => 'number', 'default' => 1, 'min' => 0, 'max' => 100, 'help' => '仅运营参考/兼容；实际价格以文章付费设置为准。'],
                             ['key' => 'download_daily_limit', 'label' => '每日下载限制', 'type' => 'number', 'default' => 0, 'min' => 0, 'help' => '0为不限制'],
                             ['key' => 'download_link_expire', 'label' => '下载链接有效期(分钟)', 'type' => 'number', 'default' => 30, 'min' => 5, 'max' => 1440],
                             ['key' => 'download_speed_limit', 'label' => '下载速度限制(KB/s)', 'type' => 'number', 'default' => 0, 'min' => 0, 'help' => '0为不限制'],

inc/classes/settings/class-aksrt-settings-credits-payment-groups.php

@@ -62,7 +62,7 @@ trait AKSRT_Settings_Credits_Payment_Groups {
     }
 
     /**
-     * 积分功能是否启用（开关 + cms_features.download_credit 联合判定）。
+     * 积分功能是否启用（仅积分系统开关）。
      */
     public static function credits_enabled(): bool {
         return AKSRT_Settings_Credits_Runtime::credits_enabled();

inc/classes/settings/class-aksrt-settings-credits-runtime.php

@@ -204,7 +204,8 @@ class AKSRT_Settings_Credits_Runtime {
     }
 
     /**
-     * 积分功能是否启用（开关 + cms_features.download_credit 联合判定）。
+     * 积分功能是否启用。
+     * 仅看积分系统开关；不再与 cms_features.download_credit 联合（该开关表示积分购买模式，非按次扣费）。
      */
     public static function credits_enabled(): bool {
         $config = self::get_credit_settings();