The Saudi-backed Yemeni government signed a power-sharing deal with a local group seeking a separate state in the south, an agreement designed to keep the country from fracturing and pave the way for broader talks to end its five-year-old war, people familiar with the talks said. The Yemeni faction, called the Southern Transitional Council, fights alongside government forces in a U.S.-backed international coalition led by Saudi Arabia against the Iran-aligned Houthi rebels in the country‚Äôs north. But it is also seeking a separate…