Apply the asymmetric viewport buffer that already fixed mobile to desktop
multiboard feeds, and trim per-post mount cost so remounts during scroll-up
are cheaper:
- Desktop multiboard buffer goes from {600,600} to {1200,2400} (top-heavy),
matching the mobile pattern from 99c0bbfac so items stay mounted longer
when scrolling back up
- Cache feed post height estimate by CID in pretext-height-estimates so
remounts skip the Pretext text-measurement work
- Memoize CommentMedia and switch its expanded-media-store reads to atomic
selectors so it stops rerendering on unrelated store changes
- Memoize useCommentMediaInfo return so its reference is stable for memo
comparators downstream
- Stop useFetchGifFirstFrame from forcing an extra render on every post
mount by bailing out of equivalent setState calls
- Extract PendingModerationActions out of PostInfo so the two
usePublishCommentModeration calls only run on the post page when
mod-approval is actually pending, not on every feed item
Board browsing, catalog filtering, post publishing, and reply publishing had little or no honest whole-repo coverage, which let route-level regressions and duplicated form side effects slip through. This pass adds targeted tests for those user flows and fixes the duplicate `PostFormTable` mounting bug they exposed.
Tommaso Casaburi