fix(db migration 9): filename property wasn't written correctly

Author: Computerdores

src/tagstudio/core/library/alchemy/library.py

@@ -598,6 +598,8 @@ def open_sqlite_library(
             logger.info(f"[Library] Library migrated to DB version {DB_VERSION}")
 
             # check if folder matching current path exists already
+            # NOTE: this has been causing new Folders to be created when the library is moved, since
+            # its introduction
             self.folder = session.scalar(select(Folder).where(Folder.path == library_dir))
             if not self.folder:
                 folder = Folder(
@@ -686,7 +688,8 @@ def __apply_db9_migration(self, session: Session, __library_dir__: Path):
 
         # Populate the new filename column.
         for entry in self.__all_entries(session):
-            session.merge(entry).filename = entry.path.name
+            entry.filename = entry.path.name
+            session.merge(entry)
         session.flush()
         logger.info("[Library][Migration][9] Populated filename column in entries table")