ONE IMPERATIVE OF my decorating is candlelight,” says author and architectural historian Michael Henry Adams of his Harlem apartment, dense with objects, layered with meaning and, since it’s at the back of the building, lacking in much natural light. And so he lights candles, even during the day. He has been that lone figure shining a light, voicing his rage, at times getting arrested protesting the demolition of Harlem and New York City history, church by church, building by building. He’s been at it since 1985, when he arrived from his hometown of Akron, Ohio, with the intention of attending the historic-preservation program at Columbia University, “which I eventually did,” Adams says, after stints as a messenger on Wall Street and a bookseller at Scribner’s and working for designer Thomas…