What is the meaning of a wife's inability to uphold Allah's boundaries with her husband, and what are the legal implications of that in Islamic law?

The meaning of a woman's inability to uphold the hudud (limits/laws) of Allah with her husband is her inability to fulfill her obligatory duties towards him due to her dislike for him. This is precisely what the Sharia has permitted her to seek khulu‘ (divorce at the wife's instance) for, in exchange for compensation, based on the Almighty's saying: "And if you fear that they will not uphold the limits of Allah, then there is no blame upon them for what she gives in return." (Quran 2:229). Al-Qurtubi interpreted this verse to mean that if each party suspects they will not fulfill the marital rights of the other due to aversion. Ibn Qudamah mentioned that if a woman dislikes her husband for any reason and fears she will not fulfill her duty of obedience to Allah, it is permissible for her to seek khulu‘ from him.