Split IFriendRequestService into command and query interfaces, refactor related services and tests, and update dependency injection. Add HubResult response model and a SignalR HubExceptionFilter for consistent error handling. Move and update FriendsHub to use new command service and result pattern. Update username validation to allow digits after Cyrillic letters. Add new controllers and configuration for SignalR. Remove obsolete IFriendRequestService and related code.
Introduces Friendship and PrivateChat models, repository interfaces, and implementations for managing friendships. Adds validators and comprehensive unit and integration tests for friendship logic. Updates InviteUserController with new endpoints and restricts access to admin role. Removes unnecessary project references from Govor.API.csproj and registers new DbSets in GovorDbContext.
Moved service implementations and interfaces from Govor.API and Govor.Core to new Govor.Application and Govor.Contracts projects. Updated namespaces and references throughout the solution. Added custom exception classes for authentication and invite services. Adjusted dependency injection and project references to use the new structure. This refactor improves separation of concerns and prepares the codebase for better maintainability and scalability.