Cumulative stellar mass assembly as a function of age for the four radial zones. Shades represent 1σ uncertainties as extracted from the PANCAKE’s metadata bootstrapping results. The core (red) shows the most rapid assembly, reaching its mass plateau early, while the outskirts (blue) exhibit a protracted growth history, reaching their final mass nearly 1 Gyr later. This radial gradient in assembly time is indicative of inside-out growth and is consistent with quenching driven by environmental interactions with the Milky Way halo rather than reionization alone.