BYRON BAY — It’s a scene that is repeated almost every evening. Small groups form on the seafront, some take out a guitar around an improvised campfire among the rocks, a few acrobats hypnotize passers-by by twirling fiery bolas, and most clink glasses over a few beers, modestly covered by paper bags. They are all there to admire the sun setting behind the mountains bordering the northern tip of the beach, which stretches for about 30 kilometers, tinting the sky with shades ranging from…