PX4/PX4-Autopilot ? reverse-engineered prompt

I want to get this PX4 autopilot project building and running locally in simulation.

Please set it up so I can clone it, build it, and launch a simple SITL test flight with QGroundControl, using the quickest path that works on a normal dev machine. If there are any missing steps, configs, or environment issues, fix them or add clear setup instructions so the whole flow is smooth. I’d also like the default build to be reliable for the common PX4 targets and not require me to guess which commands to run.

Make sure the repo still supports the usual PX4 workflow for drones and other unmanned vehicles, and keep the result friendly for someone who just wants to try it and then start iterating. Look up current docs online if you need to, and update anything outdated that would block a fresh build.