feat: odometer in trips/overview, trips upload toggle, fix video count

- OBD odometer now logged to tracking rows on every GPS snapshot
- trips table: START_ODOMETER/END_ODOMETER columns (migration)
- build_trip_summaries: picks odometer from first/last tracking row
- list_trips: uses real OBD odo, falls back to cumulative distance
- overview stats: odometer_km (max seen from OBD), video_count fixed
- history page: Odometer column shows start→end km per trip
- app_upload: TRIPS_UPLOAD_SETTING_KEY, is_trips_upload_enabled()
- _upload_tracking_batch: skips when trips upload is off
- settings: separate 'Upload trips & GPS' toggle from dashcam toggle

Co-authored-by: Copilot <[email protected]>

templates/settings.html

@@ -25,10 +25,13 @@
         </div>
         <div class="card-body py-3">
             <div class="form-check form-switch mb-2">
+                <input class="form-check-input" type="checkbox" role="switch" id="trips-upload-enabled">
+                <label class="form-check-label" for="trips-upload-enabled">Upload trips &amp; GPS logs to server</label>
+            </div>
+            <div class="form-check form-switch mb-2">
                 <input class="form-check-input" type="checkbox" role="switch" id="dashcam-upload-enabled">
-                <label class="form-check-label" for="dashcam-upload-enabled">Upload dashcam videos to server</label>
+                <label class="form-check-label" for="dashcam-upload-enabled">Upload dashcam videos to server (WiFi only)</label>
             </div>
-            <p class="text-muted small mb-2">Trip/GPS always uploads. Dashcam video only over WiFi/Ethernet.</p>
             <p id="upload-health" class="small text-muted mb-3">Checking…</p>
             <div class="d-flex align-items-center gap-2">
                 <label class="form-label mb-0 text-nowrap" for="retention-days">Delete after</label>