Is the Hadith: "Those who love each other for My glory will have pulpits of light that the Prophets and martyrs will envy," specific to same-sex love, or does it include a man's love for a woman before or after marriage, as long as it is love for the sake of Allah?

This sentence is a sacred hadith (Hadith Qudsi), not a Quranic verse. Love for the sake of Allah is not exclusive to the same gender. It is permissible for a woman to love a man for the sake of Allah. This is evidenced by our devotion to loving the Ansar, both men and women, and likewise, that a person loves another only for the sake of Allah, which includes both men and women.