HONG KONG — World shares were mixed and oil prices slipped on Thursday as conflict escalated in the Middle East, with Iran and the U.S. launching fresh attacks.U.S. futures were little changed.The United States launched more airstrikes on Iran, and Iran responded by firing at Bahrain, Kuwait and Qatar, a day after U.S. President Donald Trump said their temporary ceasefire was “over.” The prospects for a lasting peace remained uncertain, with high-level talks seeking to salvage an interim agreement on ending the war still underway, according to a regional intelligence official involved in the mediation efforts who spoke on condition…