Introduced interfaces and services for tracking user online status, including IOnlineUserStore, IUserNotificationScopeService, and IUserPresenceReader. Added PresenceHub for real-time presence updates via SignalR. Updated OnlinePingingController to use new services and return online status and last seen. Extended UserDto with IsOnline property. Updated dependency injection and privacy settings enum. Removed obsolete IUserPresenceService.
Reworked message loading endpoints and services to support flexible message querying with 'before' and 'after' parameters via a new MessageQuery contract. Updated controller actions, service interfaces, and implementations to use the new query model, and improved error handling. Added integration tests for ChatLoadController and introduced IUserPresenceService interface. Minor fixes and help text improvements in console client commands.
Introduces OnlinePingingController and related integration/unit tests for user online status updates. Adds PingHandlerService with memory cache throttling, IPingHandlerService interface, and service registration. Implements VerifyFriendship service and interface for friendship validation, with exception handling. Refactors CurrentUserService for improved user ID extraction and testability. Updates ChatsHub to verify friendship before messaging. Cleans up MediaController and optimizes UsersRepository queries by removing unnecessary includes.