Once a gap opened — a backgrounded tab during the bots' turns was
enough — the mark-seen condition (exactly one move behind) could
never hold again, so the banner grew with every move a player watched
happen in front of them. Now only the first state after arriving (or
reconnecting) announces a gap; while present and visible, play marks
itself seen, an announced gap stays frozen until watched or skipped,
and a hidden tab still accumulates its gap honestly.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>