feat: switch GPS map to Esri satellite imagery layer

Replace OpenStreetMap tiles with Esri World Imagery for high-resolution
satellite view on the GPS Tracking live map.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/pages/GpsTracking.tsx

@@ -356,8 +356,9 @@ export function GpsTracking() {
                   style={{ height: '100%', width: '100%' }}
                 >
                   <TileLayer
-                    attribution='&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a>'
-                    url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
+                    attribution='Tiles &copy; Esri &mdash; Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrid, IGN, IGP, UPR-EGP, and the GIS User Community'
+                    url="https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}"
+                    maxZoom={19}
                   />
                   {locations && <MapFitBounds locations={locations} />}
                   {locations?.filter(l => l.location).map((driver) => (