Restore scroll position when navigating back to a list

[tassilogravura]

Description

React Router v5 has no scroll restoration, so the app relied on the browser's native restoration. That doesn't work for the list views: at the point the history entry is popped, the list content hasn't been fetched and rendered yet, so the document is one viewport tall and the position is clamped to the top. Nothing scrolls back once the content arrives, leaving the user at the top of the list.

Record the scroll position for each history entry and re-apply it on POP until the page is able to scroll there, holding it briefly while the list settles. Positions are kept in session storage so they survive a page reload.

Coming back to a list that was showing a page other than the first re-parses the filter from the query string, which looks like a page change to useScrollToTopOnPageChange and scrolled over the restored position, so that hook now defers to an in-progress restoration.

Related Issue

#7142

Testing

manual testing in my own browser

Screenshots

Checklist

• I have read and understood the Contributing document.
• I have read and understood the AI Usage Policy document.
• I have made corresponding changes to the documentation (if applicable).

AI Usage Disclosure

• I have used AI tools to assist with this pull request, and I have disclosed the tools and how I used them below.

• Claude Opus 5

Additional Context