feat(robot): shrink endgame think time when both sides pass

In a dead-drawn endgame — the two most recent journal moves are both
passes, so the board and the robot's rack are frozen and the robot is
bound to pass again — the robot still waited out its long late-game think
time (up to 90 min) before passing, needlessly dragging out a decided game.

Shorten that delay to a [0.8, 1.5]x band around the human's last-move think
time (the gap between the last two journal entries), clamped to [30s, 8min]
and taken as a min with the normal schedule, so the robot never moves
slower. A slow human collapses to the 8-min cap; a fast human is tracked,
with the floor keeping the robot from passing suspiciously instantly. The
anchor reads the move journal only (no schema change), stays deterministic
from the seed, and still defers to the sleep window.

RobotTurns now carries EndgamePass + OppLastMove, filled by one batched
journal query on the scan; the honest-AI single-game trigger keeps the
normal path (it moves at once). NextMoveAt (admin ETA) is left as the
normal-schedule upper bound.

docs/FUNCTIONAL.md

@@ -158,7 +158,9 @@ wins most games), aims for a close score rather than crushing or throwing the ga
 now and then plays a single move against that plan — a surprise lead or a slack move —
 yet holds to the plan once the bag empties, and plays at a human pace — short thinking
 times for most moves, the occasional long one, and a night-time pause that tracks the
-player's own day. It answers a nudge
+player's own day; once a game is clearly decided and both sides are only passing, it stops
+dragging it out, answering its forced passes at roughly the player's own pace rather than
+after a long deliberation. It answers a nudge
 within a few minutes and nudges back when the player has been away a long time. It
 carries a human-like, language-appropriate name — a fresh one each game, drawn from a wide
 international pool of real names and handles, so the arena feels populated by many different