fix(calendar): 월별 방문 카테고리 집계 반영

lib/presentation/providers/visit_provider.dart

@@ -35,6 +35,34 @@ final monthlyVisitStatsProvider =
       return repository.getMonthlyVisitStats(params.year, params.month);
     });
 
+/// 월별 카테고리별 방문 통계 Provider
+final monthlyCategoryVisitStatsProvider =
+    FutureProvider.family<Map<String, int>, ({int year, int month})>((
+      ref,
+      params,
+    ) async {
+      final repository = ref.watch(visitRepositoryProvider);
+      final restaurants = await ref.watch(restaurantListProvider.future);
+
+      final records = await repository.getVisitRecordsByDateRange(
+        startDate: DateTime(params.year, params.month, 1),
+        endDate: DateTime(params.year, params.month + 1, 0),
+      );
+
+      final categoryCount = <String, int>{};
+      for (final record in records) {
+        final restaurant = restaurants
+            .where((r) => r.id == record.restaurantId)
+            .firstOrNull;
+        if (restaurant == null) continue;
+
+        categoryCount[restaurant.category] =
+            (categoryCount[restaurant.category] ?? 0) + 1;
+      }
+
+      return categoryCount;
+    });
+
 /// 방문 기록 관리 StateNotifier
 class VisitNotifier extends StateNotifier<AsyncValue<void>> {
   final VisitRepository _repository;