Spencer6497/free-shuffle ? reverse-engineered prompt

Build me a web app that lets someone generate random running or cycling routes from a map.

I want to pick a starting point, choose a distance, and have the app draw a route that loops through a few points and ends up close to the distance I asked for. It should use map data to find nearby points, pick a random point for the middle stop, then connect everything into a sensible route on the map. If the route is too far off from the target distance, try again until it gets close enough.

Please show the route visually on the map, along with the main points it used to build it, so I can understand what it came up with. Make it feel like a simple route generator for runners and cyclists, not a polished travel app. If you need to look up current Mapbox or Turf docs online, go ahead.