fix: restore tag rows after unarchiving all chats and remove unused ones after deleting all chats (#30453)

backend/open_webui/routers/chats.py

@@ -716,8 +716,10 @@ async def delete_all_user_chats(
             detail=ERROR_MESSAGES.ACCESS_PROHIBITED,
         )
 
+    tag_ids = [tag.id for tag in await Tags.get_tags_by_user_id(user.id, db=db)]
     result = await Chats.delete_chats_by_user_id(user.id, db=db)
     if result:
+        await Chats.delete_orphan_tags_for_user(tag_ids, user.id, db=db)
         await publish_event(
             request,
             EVENTS.CHAT_DELETED_ALL,
@@ -1129,8 +1131,14 @@ async def archive_all_chats(
 async def unarchive_all_chats(
     request: Request, user=Depends(get_verified_user), db: AsyncSession = Depends(get_async_session)
 ):
+    tag_ids = {
+        tag_id
+        for chat in await Chats.get_archived_chats_by_user_id(user.id, db=db)
+        for tag_id in chat.meta.get('tags', [])
+    }
     result = await Chats.unarchive_all_chats_by_user_id(user.id, db=db)
     if result:
+        await Tags.ensure_tags_exist(list(tag_ids), user.id, db=db)
         await publish_event(request, EVENTS.CHAT_UNARCHIVED, actor=user, subject_id=user.id, subject_type='user')
     return result