fix(journey): prevent duplicate skeleton entries for multi-day places (#606)

When syncing trip places to journal, places assigned to multiple days
(e.g. multi-night hotels) produced one skeleton entry per day_assignment
row. The existing dedup check only looked at DB state, not at entries
added within the same sync loop. Add the place ID to the tracking set
after insertion so the same place is never inserted twice.

server/src/services/journeyService.ts

@@ -261,6 +261,7 @@ export function syncTripPlaces(journeyId: number, tripId: number, authorId: numb
 
   for (const place of places) {
     if (existingPlaceIds.has(place.id)) continue;
+    existingPlaceIds.add(place.id);
 
     const entryDate = place.day_date || new Date().toISOString().split('T')[0];
     const entryTime = place.assignment_time || place.place_time || null;