Brandon Auman’s Sleepwalker, a feature-length version of the filmmaker’s own short, centers on a grieving mother (played by Hayden Panettiere) and her series of unyielding, nocturnal terrors. And as a recurring dream might have, there is an overwhelming sense of familiarity to Sleepwalker that lingers well after everything else has been forgotten. That nagging, been-there-done-that feeling ends up being way...