feat 97 메모 수정기능 추가

src/main/java/leets/bookmark/domain/bookmark/application/usecase/BookmarkUseCaseImpl.java

@@ -167,6 +167,11 @@ public void update(Long userId, Long bookmarkId, BookmarkUpdateRequest request,
 
         if (request.title() != null && !request.title().trim().isEmpty()) {
             bookmark.updateTitle(request.title());
+            updated = true;
+        }
+        if (request.memo() != null) {
+            bookmark.updateMemo(request.memo());
+            updated = true;
         }
 
         if (request.file() != null) {

src/main/java/leets/bookmark/domain/bookmark/domain/entity/Bookmark.java

@@ -86,4 +86,8 @@ public void updateUrl(String url) {
     public void updateCategory(Category category) {
         this.category = category;
     }
+
+    public void updateMemo(String memo) {
+        this.memo = memo;
+    }
 }