HONG KONG—Hong Kong’s deputy leader, former police officer John Lee, has signalled his intention to contest an election for the city’s top job, media has reported, which could see Beijing signing off on the first security official to run the global financial hub. Carrie Lam, the embattled incumbent leader who has seen her popularity slide, said on Monday she would not seek a second term, citing family considerations. Hong Kong selects a leader every five years under a process that the Chinese Communist Party (CCP) in Beijing oversees behind the scenes. Since the city reverted from British to Chinese rule in 1997, there have been four chief executives, all of whom have struggled to balance the democratic aspirations of some residents with the vision of CCP leaders. How Democratic the Process? The city’s 7.4 million people have no say in who leads them. City leaders are chosen in a vote …