Routes:
- routes table + CRUD helpers (db.js), GPX rtept/trkpt/wpt parser (gps.js)
- "Saved routes" screen (import/rename/recolor/delete, one active at a time)
- Route overlay on both the recording map and the past-track detail map,
toggled by an "M" button; default ON at Start when a route is selected
- Draw after real map-load via async whenMapReady(), no setTimeout
Road colors:
- per-activity configurable colors (walk/bike/run); fix walk roads (atype "w")
- get_road_points maps run -> "r" (lib.rs)
De-jitter (Savitzky-Golay):
- GPS.smoothTrackSG (quadratic LS per window, iterated, endpoints anchored)
- reversible storage: lat_smoothed/lon_smoothed + session.smoothed flag
- detail-screen tuning panel (window/iters sliders, live preview,
save smoothed / revert original, kcal recomputed on new points)
- accuracy_m column per point for later accuracy-gated recompute
Active map-button state restyled to inverted (dark glyph on translucent
white) for OLED; detail map safe-area handled in fullscreen.