After months of delays, Afghanistan government negotiators signed a peace deal Thursday with an insurgent faction led by one of the country’s most notorious warlords. The deal was signed at a ceremony attended by negotiators, the president’s national security advisor, and representatives of the Hezb-i-Islami faction of Gulbuddin Hekmattyar.Afghan and US officials applauded the agreement, however, it drew criticism from a prominent human rights organization.In a statement, the US embassy called Thursday’s accord “a step…