Phase 2 review found two sibling sites with the same bug class:
- truncate_before_user_ordinal in prompt.submit counted display_kind
timeline rows as user turns, shifting the truncation target
- rollback.restore used the old pop-loop pattern that would pop a
display_kind marker instead of the last real exchange
Both now use the same predicate (role==user and not display_kind)
matching list_recent_user_messages, /undo, /retry, and CLI resume.
Added tests for both paths.
cf258b6ae7