After a rainy start to the summer and the July Fourth weekend, the sun finally came out — and so did the people. Shore businesses saw near pre-pandemic crowds this weekend on beaches, in restaurants and at amusement parks. Experts say it points to a comeback at the Shore. But many businesses are struggling to hire enough staff for the size of the crowds. That challenge could last all summer, despite a new law signed by Gov. Phil Murphy that allows 16- to 18-year-olds to work 50-hour weeks, with parental permission.