修复套餐接续停机竞态与轮询兜底

internal/polling/queue_manager.go

@@ -98,6 +98,20 @@ func (m *PollingQueueManager) Requeue(ctx context.Context, cardID uint, taskType
 	}).Err()
 }
 
+// EnsureQueued 仅在任务当前不在分片队列中时补入任务，不覆盖已有任务的执行时间。
+func (m *PollingQueueManager) EnsureQueued(ctx context.Context, cardID uint, taskType string, nextCheckAt time.Time) (bool, error) {
+	shardID := int(cardID) % m.shardCount
+	key := constants.RedisPollingShardQueueKey(shardID, taskType)
+	added, err := m.redis.ZAddArgs(ctx, key, redis.ZAddArgs{
+		NX: true,
+		Members: []redis.Z{{
+			Score:  float64(nextCheckAt.Unix()),
+			Member: fmt.Sprintf("%d", cardID),
+		}},
+	}).Result()
+	return added > 0, err
+}
+
 // RemoveFromAllQueues 从所有分片的所有5个队列（realname/carddata/package/protect/card_status）移除指定卡
 // 修复 Bug3：旧实现漏掉 protect 队列
 func (m *PollingQueueManager) RemoveFromAllQueues(ctx context.Context, cardID uint) error {