On a single trading day in Tokyo, the old guard gave way. SoftBank Group Corp. surged past Toyota Motor Corp. to claim the title of Japan’s most valuable listed company. The moment arrived Monday as SoftBank’s market capitalization reached around 48.8 trillion yen, or $306 billion. Toyota’s slipped to roughly 45.9 trillion yen after its shares dropped 4.5 percent. Shares of the Masayoshi Son-led group jumped 14 percent. That single move added more points to the Nikkei 225 than the index gained overall. The benchmark briefly topped 67,000 for the first time. It closed up 0.9 percent at 66,934.33. Yet the broader Topix index fell 0.4 percent. The split could not have been clearer. Tech soared. Traditional industry lagged. This isn’t a fleeting crossover. SoftBank last held the top spot briefly during the 2000 internet bubble peak. Toyota had reigned since 2003, when it overtook NTT Docomo. More than two decades of manufacturing dominance ended in one AI-fueled session.…