namespace Application.Abstractions.Chat; public interface IChatConnectionTracker { Task AddAsync(string channelSID, ConnectedUser user); Task RemoveAsync(string channelSID, string connectionId); Task> GetByChannelAsync(string channelSID); Task GetCountByChannelAsync(string channelSID); // 전체 채널에 걸친 접속자 + 채널 SID (관리자 집계용) Task> GetAllAsync(); Task ClearAllAsync(); }