feat: Add geocoding functionality for trips and enhance activity search with coordinates

lib/blocs/activity/activity_bloc.dart

@@ -23,6 +23,7 @@ class ActivityBloc extends Bloc<ActivityEvent, ActivityState> {
     
     on<LoadActivities>(_onLoadActivities);
     on<SearchActivities>(_onSearchActivities);
+    on<SearchActivitiesWithCoordinates>(_onSearchActivitiesWithCoordinates);
     on<SearchActivitiesByText>(_onSearchActivitiesByText);
     on<AddActivity>(_onAddActivity);
     on<AddActivitiesBatch>(_onAddActivitiesBatch);
@@ -98,6 +99,50 @@ class ActivityBloc extends Bloc<ActivityEvent, ActivityState> {
     }
   }
 
+  /// Handles searching activities using coordinates directly (bypasses geocoding)
+  Future<void> _onSearchActivitiesWithCoordinates(
+    SearchActivitiesWithCoordinates event,
+    Emitter<ActivityState> emit,
+  ) async {
+    try {
+      // Si c'est un append (charger plus), on garde l'état actuel et on met isLoading à true
+      if (event.appendToExisting && state is ActivitySearchResults) {
+        final currentState = state as ActivitySearchResults;
+        emit(currentState.copyWith(isLoading: true));
+      } else {
+        emit(const ActivitySearching());
+      }
+      
+      final searchResults = await _placesService.searchActivitiesPaginated(
+        latitude: event.latitude,
+        longitude: event.longitude,
+        tripId: event.tripId,
+        category: event.category,
+        pageSize: event.maxResults ?? 20,
+      );
+      
+      final activities = searchResults['activities'] as List<Activity>;
+      List<Activity> finalResults;
+      
+      // Si on doit ajouter aux résultats existants
+      if (event.appendToExisting && state is ActivitySearchResults) {
+        final currentState = state as ActivitySearchResults;
+        finalResults = [...currentState.searchResults, ...activities];
+      } else {
+        finalResults = activities;
+      }
+      
+      emit(ActivitySearchResults(
+        searchResults: finalResults,
+        query: event.category?.displayName ?? 'Toutes les activités',
+        isLoading: false,
+      ));
+    } catch (e) {
+      _errorService.logError('activity_bloc', 'Erreur recherche activités avec coordonnées: $e');
+      emit(const ActivityError('Impossible de rechercher les activités'));
+    }
+  }
+
   /// Handles text-based activity search
   Future<void> _onSearchActivitiesByText(
     SearchActivitiesByText event,