fix: an imported chat shows its tags (#32454)

backend/open_webui/routers/chats.py

@@ -864,6 +864,9 @@ async def import_chats(
 
     try:
         chats = await Chats.import_chats(user.id, form_data.chats, db=db)
+        await Tags.ensure_tags_exist(
+            list({tag_id for chat in chats for tag_id in (chat.meta or {}).get('tags', [])}), user.id, db=db
+        )
         await publish_event(
             request,
             EVENTS.CHAT_IMPORTED,