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/Settings/PaymentRuntime.php

@@ -339,9 +339,16 @@ class PaymentRuntime {
             ],
             'order_types' => $types_by_level[0],
             'order_types_by_level' => $types_by_level,
+            'disabled_code_stops_commission' => !empty($settings['affiliate_disabled_code_stops_commission']),
             'window_days' => (int) CreditsRuntime::get_referral_settings()['window_days'],
             'settlement_days' => max(0, min(90, (int) ($settings['affiliate_settlement_days'] ?? 7))),
             'promotion_text' => sanitize_textarea_field((string) ($settings['pay_rebate_text_details'] ?? '')),
+            'poster' => [
+                'enabled' => !isset($settings['pay_rebate_poster_s']) || !empty($settings['pay_rebate_poster_s']),
+                'image' => esc_url_raw((string) ($settings['pay_rebate_poster_img'] ?? '')),
+                'title' => sanitize_text_field((string) ($settings['pay_rebate_poster_title'] ?? '')),
+                'description' => sanitize_text_field((string) ($settings['pay_rebate_poster_desc'] ?? '')),
+            ],
         ];
     }