feat(affiliate): attribution modes, settlement hardening, trusted proxies, QR and poster

- 归因模式可配置（first_touch/last_touch）、停佣开关、懒结算与佣金基数降级复查
- aksrt_get_client_ip 接入 aksrt_trusted_proxies 信任代理名单，防 CDN 头伪造
- 收益页 Canvas 二维码 + 750x1000 推广海报（本地打包 qrcode.min.js，无 CDN）
- 契约测试固化归因/海报/信任代理链路

src/Payment/CommissionLedger.php

@@ -57,6 +57,11 @@ final class CommissionLedger {
 		if ($order_no === '' || $buyer <= 0 || $amount->minor() <= 0) return 0;
         $promoter = ReferralAttribution::get_instance()->resolve($buyer);
         if ($promoter <= 0) return 0;
+        // 开关开启时，推广者的推广码已被禁用（或缺失）则不再产生新佣金。
+        if (!empty($settings['disabled_code_stops_commission'])
+            && !ReferralAttribution::get_instance()->is_promoter_code_active($promoter)) {
+            return 0;
+        }
         // 返佣订单类型按推广者会员等级分档（参考主题：每档独立勾选）。
         $promoter_level = function_exists('aksrt_get_user_vip_level') ? (int) aksrt_get_user_vip_level($promoter) : 0;
         if (!in_array($order_type, \AKSRT\Settings\PaymentRuntime::affiliate_order_types_for_level($promoter_level), true)) return 0;
@@ -98,6 +103,14 @@ final class CommissionLedger {
         foreach ((array) $rows as $row) if ($this->settle_one((int)$row['id'])) $count++;
         return $count;
     }
+    /** 懒结算兜底：收益相关入口顺带结算到期佣金，弥补 wp-cron 在低流量站点的时效缺口。 */
+    private static bool $lazy_settled = false;
+    public function lazy_settle_due(): void {
+        if (self::$lazy_settled) return;
+        self::$lazy_settled = true;
+        if (!\AKSRT\Settings\Settings::affiliate_enabled()) return;
+        $this->settle_due(20);
+    }
     private function settle_one(int $id, string $operation_key = '') {
         global $wpdb; $table = $this->table('commission_ledger');
 		$row = $wpdb->get_row($wpdb->prepare("SELECT * FROM {$table} WHERE id=%d", $id), ARRAY_A);
@@ -228,6 +241,7 @@ final class CommissionLedger {
 		return $negative ? -$minor : $minor;
 	}
     public function overview(int $user_id): array {
+        $this->lazy_settle_due();
         global $wpdb; $table=$this->table('commission_ledger');
         $row=$wpdb->get_row($wpdb->prepare("SELECT COALESCE(SUM(original_amount+adjustment_total),0) total, COALESCE(SUM(CASE WHEN status='pending' THEN original_amount+adjustment_total ELSE 0 END),0) pending, COALESCE(SUM(CASE WHEN status='settled' THEN original_amount+adjustment_total ELSE 0 END),0) settled FROM {$table} WHERE promoter_id=%d",$user_id),ARRAY_A) ?: [];
 		$withdrawn = '0.00';