Do Hanafis believe that the Holy Qur’an is a judge over and dominant over the Sunnah, and that the Sunnah does not abrogate or add rulings not mentioned therein, but rather its role is limited to explaining and clarifying its general commands?

We have not found the phrase "the Sunnah (definition) does not add a ruling not mentioned in the Qur'an" in Hanafi books. What has been narrated from the Salaf is "the Sunnah is a judge over the Qur'an," meaning it interprets and clarifies it. Hanafis believe that the Qur'an can be abrogated by the Mutawatir and Mashhur Sunnah, but not by Ahad (single-chain) narrations. They also believe that adding to a text is abrogation and is therefore not acceptable. For this reason, they do not hold the view of exiling the unmarried fornicator, nor do they stipulate faith in the expiation for an oath and Dhihar.