A thin, flexible insulating ring of radius \(R\) carries a net positive charge \(+Q\) distributed uniformly along its circumference. A point charge \(+q\) is held fixed at the center of the ring. An external force slowly compresses the ring symmetrically, reducing its radius to \(\dfrac{R}{2}\) while keeping the point charge fixed at the center. What is the work done by the external force on the ring-charge system during this compression?