Rehabilitating Johnny Castaway for the browser

In 1992, Dynamix and Sierra On-Line released Johnny Castaway. Your Windows 3.1 PC went idle and Johnny fished, slept, built rafts, and got into trouble on his island. As a young kid, I came across him during a summer holiday trip to my parents' office. Thirty-four years later, he is hard to visit. Sharing it with my kid means dragging a beige tower out of a closet or faffing about with a virtual machine. That is enough friction that almost nobody bothers, and a far cry from the little moment of joy when Johnny just did his thing on the side. Now he spends his days in my browser tab. Rebuilding his island paradise faithfully in JavaScript was only feasible with AI assistance; by hand, it would have been weeks of detailed full-time work. Earlier ports got a long way, and this one builds on them, but as far as I can tell none had been checked tick by tick against the original program (if I've missed one, please tell me). tl;dr Johnny's island combines scripted gags and weighted random…