It looks like the event-planners for most of the District’s book stores are still on vacation, so it’s slim pickings for you bookworms out there. Fortunately, Politics and Prose is picking up the slack with a few notable author events. Chicklit-erati beware: this week’s offerings tend more toward the academic set. THURSDAY Daniel Mendelsohn will be reading from his book, The Lost: A Search for Six of Six Million, about his historical detective work retracing…