[Feat] Add debug logging for zoomLevel in MemberPlaceService.java

Author: KOKEONHO

src/main/java/boombimapi/domain/place/application/MemberPlaceService.java

@@ -135,6 +135,8 @@ public List<ViewportNodeResponse> getViewportNodes(
         ViewportRequest request
     ) {
 
+        log.info("[MemberPlaceService] getViewportNodes() zoomLevel: {}", request.zoomLevel());
+
         // 1) 뷰포트 경계 계산
         double lat1 = request.topLeft().latitude();
         double lng1 = request.topLeft().longitude();