Is there a clear text in the Quran or Sunnah indicating that the Quran is uncreated, and must one declare as an infidel anyone who says it is created, bearing in mind that Jesus, son of Mary, is "the word of Allah" and he is created, so why would the Quran not be the same without disabling or likening the attributes of Allah?

The entire methodology of theلف (Salaf) is that the Qur'an is the uncreated, revealed speech of Allah. Allah spoke it in reality, with sound and letters, and it is an attribute among His attributes. Discussion of the attributes is a branch of discussion of the essence. Therefore, whoever believes that the attribute of speech or any other attribute of Allah is created has committed an act of disbelief (kufr). The Qur'an and Sunnah have indicated that the Qur'an is the speech of Allah the Almighty and that speech is an attribute subsisting in Him, glorified be He. The innovation of saying that the Qur'an is created occurred after the generation of the Companions, and the Mu'tazilah bore the brunt of it. As for naming Jesus (peace be upon him) "the Word of Allah," it is because he was created by the word "Be!" (kun), and it does not mean that he is the Word itself, for Jesus is a created human being.