feat: simulated odometer in trip replay + trip list (continuous across trips)

- Pi route_points: emit per-point odometer (raw OBD value or baseline+prior+within-trip distance)
- Pi get_trip_route: SELECT ODOMETER, compute prior-trips distance + baseline
- Pi list_trips: fallback now starts from baseline (was 0)
- Server get_trip_route: per-point odometer (raw or simulated) with haversine accumulation
- Server list_trips: odo_start/end from baseline + cumulative (was hardcoded None)
- history.js: Odometer line in replay scrubber below speed
- Both history templates: trip-replay-odometer element

templates/history.html

@@ -70,6 +70,7 @@
                         <strong id="trip-replay-time"></strong>
                         <span id="trip-replay-speed" class="text-muted"></span>
                     </div>
+                    <div id="trip-replay-odometer" class="text-muted mt-1" style="font-size:0.75rem;min-height:1rem"></div>
                     <div id="trip-replay-location" class="text-muted mt-1" style="font-size:0.75rem;min-height:1rem"></div>
                 </div>
             </div>