feat(douyu): 兑换成功后自动刷新积分 & 修复兑换图片首开裂图

- 兑换成功后自动调用积分查询，更新账号最新积分并写入任务结果
- 兑换图片并发生成竞态修复：同任务共享 in-flight Promise，避免 revoke 导致裂图
- 兑换图片移除积分展示

web/backend/services/douyu_runner.py

@@ -1830,6 +1830,12 @@ class DouyuBatchRunner:
         )
         account.bind_status = "goods_exchanged"
         account.updated_at = datetime.now(timezone.utc)
+        # 兑换成功后自动刷新积分，更新账号最新积分信息（失败不阻断兑换成功）
+        points_refresh = None
+        try:
+            points_refresh = self._refresh_account_points(client, account, cookie, ctn=ctn)
+        except Exception as exc:
+            self._push_log("warning", f"兑换后刷新积分失败: {exc}")
         self._mark_task(
             db,
             task,
@@ -1841,6 +1847,7 @@ class DouyuBatchRunner:
                 "game_channel": account.game_channel or "",
                 "account_name": account.nickname or account.username or account.uid or f"#{account.id}",
                 **result,
+                **(points_refresh or {}),
             },
         )