Discussion open-scroll: land at start of latest reply item (poll or comment)

[Copilot]

Opening a long discussion from list view currently jumps to the bottom of the latest reply, which hides the beginning of that message. This change makes discussion open-scroll anchor to the start of the latest reply item instead.

• Behavior change (discussion threads)

  • In frontend/src/components/CommentsArea.vue, default open-scroll now targets the latest reply item across both comments and polls (whichever is newer by creation) when no explicit comment/poll query is present and navigation is not from search.
  • This behavior is triggered from both comments and polls onSuccess handlers to stay correct regardless of load order.
  • Non-discussion timelines keep existing behavior (scrollToEnd()).

• Element targeting reliability

  • Uses keyed timeline element refs (timelineItemElements) populated via setItemRef(...).
  • Reuses getTimelineItemKey for:
    • latest-reply anchor lookup
    • scrollToItem
    • getCommentContentElement

• Representative diff

  // before: discussions opened to bottom/end
  } else if (!route.query.fromSearch && comments.data?.length > 0) {
    scrollToEnd()
  }
  
  // after: discussions open at top of latest reply item (poll or comment)
  } else if (!route.query.fromSearch && comments.data?.length > 0) {
    if (shouldScrollToLatestDiscussionReply()) {
      scrollToLatestReply()
    } else {
      scrollToEnd()
    }
  }

Original prompt

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This section details on the original issue you should resolve

<issue_title>UX: Opening a new thread should jump at start of last reply, not end</issue_title>
<issue_description>Steps:

1. Find a long running thread with a reply that's longer than what fits in your screen
2. Open thread from list view, it goes to end of the message and not start.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes UX: Opening a new thread should jump at start of last reply, not end #390

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[netchampfaris]

@copilot instead of the start of last "comment" it should be scrolled to start of last poll or comment

[cypress]

gameplan    Run #405

Run Properties:   Passed #405  •  f3bda189d5 ℹ️: Merge 80ad09576d598c9f25681c7fd4708f94f18e9641 into 7ab03f2d4c5ac04b2d26db9107f5...

Project	gameplan
Branch Review	copilot/fix-thread-jump-location
Run status	Passed #405
Run duration	00m 52s
Commit	f3bda189d5 ℹ️: Merge 80ad09576d598c9f25681c7fd4708f94f18e9641 into 7ab03f2d4c5ac04b2d26db9107f5...
Committer	Copilot
View all properties for this run ↗︎

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View all changes introduced in this branch ↗︎

[Copilot]

@copilot instead of the start of last "comment" it should be scrolled to start of last poll or comment

Updated in commit f32d488 — default discussion open-scroll now targets the latest reply item across both polls and comments (whichever is newer), and still anchors to the start of that item.

Screenshot: