Addendum to the NA61/SHINE Proposal: Request for light ions beams in Run 4

This addendum presents the NA61/SHINE request for oxygen, magnesium, and boron beams at 13$A$ GeV/$c$, 30$A$ GeV/$c$, and 150$A$ GeV/$c$ in the Run 4 period. The beam will be used to perform unique measurements needed to study the diagram of high-energy nuclear collisions. In particular, they will uncover the changeover between the string hadron-production mechanism in interactions of light nuclei and the QGP formation-hadronization in heavy-ion collisions.