fix(map): prevent ghost polylines and improve ETA accuracy.

- Added cancel tokens to avoid 'traces' on map after route removal.
- Fixed math bug in ETA proportion calculating 16.6% less time than real.
- Set average bus speed to 30km/h for more realistic calculations.

frontend/src/composables/useFlujoPrincipal.ts

@@ -116,7 +116,7 @@ export const useFlujoPrincipal = () => {
                 return;
             }
 
-            await encontrarParadaCercana(ubicacion, paradas, map)
+            await encontrarParadaCercana(ubicacion, paradas, map, cancelToken)
             const paradaCercanaFound = paradaCercana.value
 
             if (cancelToken?.cancelled || routeStore.selectedRouteId !== _ruta.id) {