## Why
The command center seeded only ten recent sessions, with no way to browse older history from the task list.
## What changed
- Add a keyboard-selectable “Show more” row that discovers up to ten more tasks, with loading and retry states that remain accessible during search.
- Retain per-source cursors and buffered rows across requests, merging interactive and non-interactive history by recency without discarding existing tasks on failure.
- Refill vacancies after tasks are archived or deleted, and prevent stale refreshes from restoring removed tasks.
- Limit routine detail refreshes to recent and loaded tasks, plus explicitly targeted threads, as retained history grows.
## Testing
Add regression coverage for pagination across mixed sources, cursor retries without row loss, automatic refill, queued pagination, and “Show more” navigation, loading, search, and retry rendering.
GitOrigin-RevId: 0bfcc970c9adf0c8d509b275a92ecf01c29595ad
Benjamin Carlsson
8f6517772b