No custom Planetiler profile needed after all — Maptool::HikingTrails
runs osmium tags-filter r/route=hiking against the same .osm.pbf
PmtilesBuilder already downloads per country for offline.pmtiles, then
osmium cat -f opl (locations_on_ways=true) to get member-way geometry
back as plain text, no separate node-id lookup table to build.
No general OSM tool stitches a route relation into one line (routes
are a semantic grouping, not a geometry type) — parse_opl does that
walk itself, same as the Overpass-based click handler already does
client-side. Kept pure/testable apart from the two osmium subprocess
calls, mirroring OverpassPois.fetch vs .to_geojson.
rake hiking:trails[pbf,out] to try it by hand against a real cached
extract. Not wired into the actual offline build or rendering yet —
still just a prototype, per TODO.adoc.
