FIX: 158 - Ensure GTFS and RAPTOR router have the same stop set

- Add all stops to RAPTOR, even if they have no departures / stopping trips.
- When transfers are generated, it could be that connections from or to stops with no trips are available via a footpath / transfer as first or last leg.

src/main/java/ch/naviqore/service/gtfs/raptor/convert/GtfsToRaptorConverter.java

@@ -1,9 +1,6 @@
 package ch.naviqore.service.gtfs.raptor.convert;
 
-import ch.naviqore.gtfs.schedule.model.GtfsSchedule;
-import ch.naviqore.gtfs.schedule.model.Stop;
-import ch.naviqore.gtfs.schedule.model.StopTime;
-import ch.naviqore.gtfs.schedule.model.Transfer;
+import ch.naviqore.gtfs.schedule.model.*;
 import ch.naviqore.gtfs.schedule.type.TransferType;
 import ch.naviqore.raptor.router.RaptorConfig;
 import ch.naviqore.raptor.router.RaptorRouter;
@@ -47,7 +44,13 @@ public GtfsToRaptorConverter(GtfsSchedule schedule, List<TransferGenerator.Trans
     public RaptorRouter convert() {
         log.info("Converting {} trips from GTFS schedule to Raptor data model", schedule.getTrips().size());
 
-        for (var route : schedule.getRoutes().values()) {
+        for (Stop stop : schedule.getStops().values()) {
+            String stopId = stop.getId();
+            builder.addStop(stopId);
+            addedStops.add(stopId);
+        }
+
+        for (Route route : schedule.getRoutes().values()) {
             for (GtfsRoutePartitioner.SubRoute subRoute : partitioner.getSubRoutes(route)) {
                 addRoute(subRoute);
             }
@@ -60,17 +63,8 @@ public RaptorRouter convert() {
 
     // add raptor route for each sub route of the gtfs routes
     private void addRoute(GtfsRoutePartitioner.SubRoute subRoute) {
-
-        // add stops of sub route that are not already added
-        List<String> stopIds = subRoute.getStopsSequence().stream().map(Stop::getId).toList();
-        for (String stopId : stopIds) {
-            if (!addedStops.contains(stopId)) {
-                builder.addStop(stopId);
-                addedStops.add(stopId);
-            }
-        }
-
         // add sub route as raptor route
+        List<String> stopIds = subRoute.getStopsSequence().stream().map(Stop::getId).toList();
         builder.addRoute(subRoute.getId(), stopIds);
 
         // add trips of sub route
@@ -88,11 +82,11 @@ private void addRoute(GtfsRoutePartitioner.SubRoute subRoute) {
     /**
      * Processes all types of transfers, ensuring the correct order of precedence:
      * <p>
-     * 1. Additional transfers: These transfers have the lowest priority and are processed first.
-     * 2. Parent-child derived transfers: If a transfer is defined between two parent stops (e.g., A to B), this method
-     * derives corresponding transfers for their child stops (e.g., A1, A2, ... to B1, B2, ...).
-     * 3. GTFS schedule-defined transfers: Transfers explicitly defined in the GTFS schedule (e.g., A1 to B2) take the
-     * highest priority and are applied last, thereby overwriting transfers previously derived from parent stops.
+     * 1. Additional transfers: These transfers have the lowest priority and are processed first. 2. Parent-child
+     * derived transfers: If a transfer is defined between two parent stops (e.g., A to B), this method derives
+     * corresponding transfers for their child stops (e.g., A1, A2, ... to B1, B2, ...). 3. GTFS schedule-defined
+     * transfers: Transfers explicitly defined in the GTFS schedule (e.g., A1 to B2) take the highest priority and are
+     * applied last, thereby overwriting transfers previously derived from parent stops.
      * <p>
      * The method ensures that all transfers, whether additional, derived, or explicitly defined, are handled in the
      * correct priority order.