Refactor app architecture and clean local artifacts

Backend/Repositories/IUserSessionRepository.cs

@@ -0,0 +1,11 @@
+using Backend.Domain;
+
+namespace Backend.Repositories;
+
+public interface IUserSessionRepository
+{
+    Task<UserSession?> GetActiveByTokenAsync(string token, CancellationToken cancellationToken = default);
+    Task<int> CountRecentSessionsFromIpAsync(string ipAddress, DateTimeOffset since, CancellationToken cancellationToken = default);
+    void Add(UserSession session);
+    Task SaveChangesAsync(CancellationToken cancellationToken = default);
+}