fix: 星阙V3提现强制用全局证书配置，修复序列号与私钥不匹配

club表私钥路径/序列号错填会导致微信报证书序列号错误。
xq 提现改读 settings+写死序列号；build_authorization 双重兜底。

Co-authored-by: Cursor <cursoragent@cursor.com>

jituan/management/commands/seed_club_xq.py

@@ -6,7 +6,7 @@ from django.conf import settings
 from django.core.management.base import BaseCommand
 from django.db import transaction
 
-from jituan.constants import CLUB_ID_DEFAULT
+from jituan.services.wechat_pay import WX_V3_CERT_SERIAL_NO_OVERRIDE
 from jituan.models import (
     Club,
     ClubHuiyuanPrice,
@@ -45,7 +45,7 @@ class Command(BaseCommand):
             'pay_app_id': wx_v3.get('APPID', '') or getattr(settings, 'WEIXIN_APPID', ''),
             'mch_key': getattr(settings, 'WEIXIN_SHANGHUMIYAO', ''),
             'api_v3_key': wx_v3.get('API_V3_KEY', ''),
-            'cert_serial_no': wx_v3.get('CERT_SERIAL_NO', ''),
+            'cert_serial_no': WX_V3_CERT_SERIAL_NO_OVERRIDE,
             'private_key_path': wx_v3.get('PRIVATE_KEY_PATH', ''),
             'platform_cert_dir': wx_v3.get('PLATFORM_CERT_DIR', ''),
             'config_json': {