Fratres-X-AI/JamBoy ? reverse-engineered prompt

Build me a Python project for GPS denied drone navigation that takes a downward camera feed, IMU data, and barometer altitude, then estimates position and velocity without GPS. I want it to use optical flow for ground speed, offline map matching for an absolute location fix, and an EKF to fuse everything together. It should also have a simple navigation state machine for cruise, dead reckoning, terminal, and abort, plus a MAVLink output path for sending vision position updates to a flight controller or simulator.

Please make it work from a clean setup with a quickstart script that generates dummy data, runs tests, and confirms the sim passes. Keep it sim validated, not flight certified, and include clear docs for how to run it on Linux and a lighter Windows path if some geo libraries are missing. If useful, look up current docs online for any library details, but keep the app itself focused on the navigation layer and the simulation workflow.