KABUL, Afghanistan (AP) — Afghanistan's two presidential candidates were set to a sign a power-sharing deal on national TV on Sunday, three months after a disputed runoff that threatened to plunge the country into turmoil and complicate the withdrawal of U.S. and foreign troops. U.N. and Afghan election officials spent weeks auditing the runoff results after allegations of fraud, a common occurrence over Afghanistan's last two presidential elections. [...] high-stakes negotiations -- and not a precise vote tally -- appear to have settled the country's power structure.