No, compressing a magnet to the size of an atom would not provide it with enough energy to reach the speed of light. The speed of light in a vacuum is an absolute limit in our universe, and objects with mass cannot reach or exceed this speed.
The energy required to accelerate an object with mass to the speed of light would be infinite according to our current understanding of physics. As an object with mass approaches the speed of light, its relativistic mass increases, and it requires increasingly more energy to accelerate it further. At the speed of light, an object with mass would require an infinite amount of energy, which is not attainable.
Compressing a magnet to the size of an atom would not change the fundamental properties of the magnet or alter the limitations imposed by the laws of physics. While compression may lead to changes in the magnet's behavior at the atomic level, it would not provide the necessary conditions to overcome the energy requirements and allow it to reach or exceed the speed of light.
Therefore, it remains impossible for any object with mass, regardless of its size or composition, to travel at or surpass the speed of light.