Hong Kong’s embattled leader resurfaced for the first time in a week for a morale-boosting meeting with police union leaders on Thursday, after a six-hour siege of the force’s headquarters the night before by hundreds of protesters demanding she completely withdraw the government’s now-suspended extradition bill.Chief Executive Carrie Lam Cheng Yuet-ngor’s office issued a statement announcing she had met the heads of four staff associations representing the city’s 30,000 officers at Government…