Samsung Electronics’ co-CEOs struck a cautious tone Friday ahead of the tech giant’s 57th anniversary. Jun Young-hyun, head of the device solutions division, warned that record profits do not mean a full recovery in technological competitiveness, while Roh Tae-moon, who leads the device eXperience division, called for tighter cost controls. The two delivered separate anniversary messages to employees as the company prepares to mark the occasion Sunday without a formal ceremony. Their remarks cam