For GPX files with one long track segment, extracting only start/end
gives just 2 waypoints. Now uses Douglas-Peucker line simplification
(epsilon=0.05° ≈ 5km) to find significant turning points.
Result: berlin-dresden-radweg (249km, 5660 points) → 10 waypoints
that capture the route's key direction changes.
Multi-segment GPX files still use segment endpoints as before.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Both new.tsx and api.sessions.ts had duplicated track-segment
waypoint extraction logic. Moved to packages/gpx as
extractWaypoints(gpxData) — uses <wpt> elements when present,
falls back to start of each track segment + end of last.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
