Wait for the host to press "next hand" on every table

Previously only the review CPU table paused after each hand; cash-only,
friends and CPU tables moved on automatically after a short delay. Now
every table keeps the result on screen until the host presses 次のハンドへ,
and the next hand is dealt right away. If the host has left, the new host
presses it; with no human seated the table still advances on its own.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/seating.test.js

@@ -61,6 +61,7 @@ test('席順: ハンド中は次のハンドの始めに並べ替え、ボタン
   // 全員降りてハンドを終わらせ、次のハンドへ
   for (let i = 0; i < 10 && !h.finished; i++) t.act(t.seats[h.toAct].token, 'fold', 0);
   assert.ok(h.finished);
+  assert.equal(t.nextHand(T(0), 0), null);
   t.tick(10 ** 6);
   t.tick(10 ** 7);
   assert.equal(t.hand.number, 2);
@@ -84,6 +85,7 @@ test('席順: 決めた後に座った人は最後に加え、いなくなった
   t.join(T(5), 'p5'); // ハンド中に新しく座る
   t.leave(T(1)); // ハンド中に退席
   for (let i = 0; i < 10 && !h.finished; i++) t.act(t.seats[h.toAct].token, 'fold', 0);
+  assert.equal(t.nextHand(T(0), 0), null);
   t.tick(10 ** 6);
   t.tick(10 ** 7);
   assert.deepEqual(names(t), ['p2', 'p0', 'p5']);