Instant access makes streaming content for kids a boon to parents, but it comes with some complications. Favorite shows disappear without warning. You can only watch the usual suspects so many times before Caillou haunts your nightmares. Amid the uncertainty, though, a hero emerges: Netflix’s family-friendly August slate, which includes a packed slate of family fare. Yes, it’s losing Clifford the Big Red Dog . But it’s gaining so much more—just in time for the next heat wave.