Texans G.M. relies on emotional detachment in overhauling roster

Two years ago, the Texans wanted to be the featured team on Hard Knocks.  Now, they’re not interested. They’re not interested because they’re getting attention the old fashioned way:  By winning football games. But the team’s first playoff berth in a decade of existence has been chased by a stunning out-with-the-old-in-with-the-new offseason, during which G.M.…