Joyva, the fourth-generation family-owned kosher candy company, has come a long way since it was first launched in 1907 as a pushcart on the Lower East Side. Now a company long associated with iconic Passover candies and other year-round treats is undergoing a rebrand — tweaking its packaging, eliminating artificial ingredients and aiming to attract a new generation of customers by calling attention to the company’s deep Brooklyn roots. We visited the Brooklyn factory to see just how the sausage