lib/maptool/overpass_pois.rb: queries Overpass for drinking water, dump stations, LPG refill, toilets, laundromats, supermarkets/ convenience stores, and springs within a bbox, writes GeoJSON. A dev-time tool (like the offline.pmtiles/terrain.pmtiles generation steps already documented) — not called by the running app, drop the output into data/gpx/ or upload it through the Tracks panel like any other .geojson layer. Verified against the real Overpass API (88 POIs for central Bratislava) in addition to the new unit tests (pure to_geojson/ build_query logic, no network in the suite itself). Full suite: 103 runs, 0 failures.