How to clean up a project from old and unused files and classes?

Question

visual studio

When creating the file, everything is ok, but if it is deleted, then it is deleted only in the project navigation in VS. But in reality, the file is still in the project folder.
Ok, we go into the project, spend a couple of hours, days searching for the left files, delete them by hand, run the build, all the deleted files are still in the Debug folder.
And how do you remove them then?
And another question, since VS keeps files forever and rebels when deleted, how then to return them to the project navigation?
Let's say I had a .h and .cpp file Test, deleted it, and now I need to return it to the project, but even though the file is in the project folder, it gives an error during the build. Of course, you can create the same files, then it will generate a new file + pull the code from the old ones, which is not a new file creation at all, but some kind of hybrid. And the delete
function" rather " hide ".
An example of creating a new object when there is already a file in the project folder.

#pragma once
class Coords2D
{
public:
  const unsigned short int x;
  const unsigned short int y;
  Coords2D(const int xAxis, const int yAxis);
};

class Coords2D
{
public:
  Coords2D();
  ~Coords2D();
};

AndroidStudio and PhPStorm, UE 4 demolish files completely instead of hiding them.
And yet, it is not entirely clear what kind of SourceFilter, when you need to create a folder, it is created in the navigation, but in reality it is not.