Added `SaveChangesAsync` to `IRepository` for async persistence.
Introduced AutoMapper and DbContext dependencies in `Repository`.
Simplified EF Core operations by removing `#if NET48` logic.
Replaced `Task.Run` with direct EF Core calls for .NET Framework.
Updated AutoMapper version for .NET 8 and added EF Core testing.
Suppressed AutoMapper vulnerability warning in project file.
Performed general cleanup and improved maintainability.