The Kremlin scrambled to evacuate residents from a border town Saturday, as Ukrainian troops quickly advanced toward a nuclear plant, four days after gaining a foothold in Russia’s southwestern Kursk region. On Friday, Ukraine knocked out an entire Russian reinforcement convoy, as fighters caught Russian troops off-guard. Video of the aftermath showing smoldering Russian trucks was shared online. Ukrainian soldiers continued to move further into Russia, reaching at least six miles into Russian territory, the deepest advance since Moscow invaded the neighboring nation in February 2022....