OSM hiking & cycling trail routing for Land mode

[radumarias]

Summary

Adds an OSM trail-routing resolver for Land mode, mirroring the existing ferry/sea routing used in Sea mode. When the user is in Land mode on the Route or Waypoints tabs, each leg is now snapped onto OpenStreetMap hiking/cycling ways and path-found through the network — instead of always drawing a straight line.

Implementation

• New src/lib/server/osm-land.ts — analog of osm-ferry.ts. Queries Overpass for ways tagged:
  • highway=path | footway | track | bridleway | cycleway | pedestrian | steps
  • foot=designated or bicycle=designated
  • Builds a geojson-path-finder graph, snaps each endpoint to the nearest vertex, returns the routed polyline + length + hike/bike way counts.
• /api/route?land=1 → calls computeLandTrailRoute first, falls back to straight-line if no network connects the endpoints.
• /api/multi-route?land=1 → each leg attempts trail routing; new trailLegs count surfaces in the response.
• RouteView.svelte adds a 🥾 Trail route via OpenStreetMap meta-line (with hike/bike way breakdown). WaypointsView.svelte adds 🥾 N trail to the track summary.
• i18n: new keys route.trailPrefix / trailWaysSuffix / trailWaysTitle / trailLabel, waypoints.trailLegs, and updated routeDesc in the help page — translated for EN / TH / RO.

Constraints

Trail networks are an order of magnitude denser than ferry ways, so:

• MAX_SPAN_DEG = 1.5 (vs 6 for ferry) — trips wider than ~165 km bail out early.
• MAX_SNAP_KM = 5 — if neither endpoint is within 5 km of a trail, fall back rather than render a confusing line.
• Bbox pad is graduated by trip length to keep Overpass payloads bounded.
• Overpass responses are cached for 24 h via the existing cached() helper.

Verified

• pnpm check — 0 errors
• pnpm test — 75/75 pass
• pnpm build — succeeds
• Manual smoke test against /api/route?from=13.7308,100.5418&to=13.7253,100.5435&land=1 (Lumpini Park, Bangkok) returns kind: 'trail', 0.91 km, 52-point polyline snapped through real paths.
• Sea-mode path unchanged (regression check passes).

Test plan

• Open the deployed preview, pick Land mode in the top toggle.
• In Route tab, pick two points within a trail-rich area (e.g., inside a park) — verify the polyline follows real paths and the meta-line shows 🥾 Trail route via OpenStreetMap with hike/bike counts.
• In Waypoints tab, drop 3+ points along a hiking area — verify the track summary shows 🥾 N trail legs.
• Pick endpoints far from any trail — verify it gracefully falls back to straight-line with a (trail: snap-too-far / no-path / span-too-wide …) hint.
• Switch back to Sea mode and confirm ferry/sea routing still works (no regression).
• Language switcher → TH and RO — verify the new meta-line strings render correctly.

https://claude.ai/code/session_01B9DMrLPT7hYfdCTsJgFF9q

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Generated by Claude Code

[radumarias]

We go with 3 from below

PR #33 adds OSM hiking/cycling trail routing for Land mode — and none of it is on main. The key files (osm-land.ts, trail i18n keys, route handler changes) don't exist.

However, it has merge conflicts (mergeable_state: "dirty") because main has diverged significantly since it was opened (all the wind compass, GPS follow, service worker changes).

What it adds (all new, not on main):

src/lib/server/osm-land.ts — Overpass query for hiking/cycling trails, path-finding via geojson-path-finder
/api/route?land=1 and /api/multi-route?land=1 snap to real trail networks instead of straight lines
Trail meta-line in RouteView/WaypointsView (🥾 Trail route via OpenStreetMap)
i18n keys for trail routing in en/th/ro
The problem: The branch is based on old main and its +server.ts / i18n files conflict heavily with the wind-direction, compass, and GPS changes we've since shipped. Rebasing or merging would require resolving conflicts in ~5-6 files.

Options:

1. Cherry-pick the trail-routing logic (osm-land.ts is self-contained) onto a fresh branch from current main, re-wire the API handlers and i18n manually — cleanest
2. Rebase PR OSM hiking & cycling trail routing for Land mode #33 onto current main — lots of conflict resolution
3. Close OSM hiking & cycling trail routing for Land mode #33 and re-implement from scratch on current main — since I wrote it originally, this is fast
   I'd recommend option 1 or 3 — want me to bring the trail routing onto current main?

[radumarias]

new impl #41