Check out BrainTool (https://braintool.org) it's a browser extension that allows you to trivially add pages to a custom hierarchal 'Topic tree' along with notes on why you're saving the page, and then to control opening and closing tabs by topic. Everything is saved to an org-mode syntax text file. So of your requirements it's persistent, local, tagged and entirely-offline-usable. Incremental search is in the works.

It works with tab groups on Chrome, Edge and Brave which adds another step toward keeping your browser organized.

It might fit your workflow and be what you need!