Caroline Framke Chief TV CriticIn its fourth and final episode, “Crime Scene: The Vanishing at the Cecil Hotel” finally gets to its point.After three episodes of unpacking the mysterious disappearance of Elisa Lam, the infamous Cecil Hotel in which she was last seen, the fraught history of downtown Los Angeles, and even several truly confusing “web sleuth” theories about what might have happened, the new Netflix series reaches a perhaps unsatisfying conclusion: that the simplest explanation is