The indictment of former first lady Kim Keon-hee on corruption charges has thrown a spotlight on the collapse of institutional checks during her husband’s presidency, prompting fresh calls to strengthen oversight and transparency measures.The wife of former president Yoon Suk-yeol was charged on Friday with stock manipulation, bribery and the receipt of illicit political funds by a team of investigators led by Special Prosecutor Min Joong-ki.This is the first time in South Korea’s history that...