Add pagination to posts/list endpoint & lazy load list's post data

In my blog I have about 300 post with about 10 images for each post. Those images are copied in the asset folder of each post following this documentation https://hexo.io/docs/asset-folders.html.
To show the images in my articles I am writing {% asset_img image.jpg %} in my posts. I don't know why each time I am trying to create a new post through hexo-admin, the admin is not responding and I am getting the message "504 Gateway Time-out" when I am trying to reload the page.
I would like to know if I am doing anything wrong and why I do have those problems.

The issue names the posts/list endpoint and the admin post list, but no files or tests. First reproduce the 504 while creating or reloading a post with many asset-folder images, then trace the endpoint and list loading path. Done means the large post collection loads through pagination and lazy post data without the reported timeout.

Written by the indexing model from the issue text.