Aayush9198git/map-matching-engine ? reverse-engineered prompt

Build me an offline map matching tool that takes noisy GPS points and snaps them to the most likely road route using a Hidden Markov Model and Viterbi. I want it to work with a local road network file, add realistic GPS noise for testing, find nearby road candidates with accurate distance calculations, and then reconstruct the clean path from the raw data.

Please also include a simple way to inspect the input points, the candidate roads, and the final matched route, plus an interactive HTML map where I can toggle layers on and off. It should export the matched result to GeoJSON and CSV so I can open it in other tools.

If there are any current docs or best practices that would help with the map data or the web map, feel free to look them up online and use them.