Mobile: load earlier thread activity automatically when scrolling to the top

[MegaWattCZE]

Written by Claude Code, an AI agent.

Problem

On mobile (Android), opening a thread after a long agent run shows only the latest page of history, topped by the Load earlier activity button. To read my own last prompt, or the agent's whole run since that prompt, I have to tap the button several times, scrolling back to the top after each page. A single long run produces many activity rows, so one page rarely reaches the prompt.

Current behaviour (from source on main)

• apps/mobile/src/features/threads/ThreadFeed.tsx: ThreadFeedLoadEarlierControl is rendered in ListHeaderComponent and only calls onLoadEarlier on press.
• The list has no onStartReached handler, so scrolling to the top of the loaded window loads nothing, and there is no pull/swipe gesture for it either.
• Pagination itself came with feat: paginate thread loading with user-anchored turn windows #5493, which deliberately added a plain header row.

Proposal

Either of these would solve it, and they combine well:

1. Auto-load on reaching the top. When the header comes into view (LegendList onStartReached, or the header's visibility), load the next older page automatically, with the button kept as a fallback for errors and for accessibility. The list already sets maintainVisibleContentPosition, so prepending should not move the content.
2. Load back to my last prompt. One tap (or the first automatic load) fetches history up to the most recent user message instead of a single fixed-size page, so the prompt and everything the agent did since then are visible together.

A pull-down gesture at the top (the reverse of pull-to-refresh) would be an acceptable alternative to (1).

The web client may have the same pattern; this request is about mobile, where repeated taps and scrolling cost the most.