The end-to-end PvP gameplay test asserted the pre-translator relay contract
(A's TurnEnd broadcasts TurnEnd+Judge to both sides). Tasks 7/8 replaced that
with the per-URI translator: the active player ends its turn by sending TurnEnd
then Judge, the opponent receives the translated {turnState:0}/{spin:0} frames,
and the sender receives nothing. Rewrote the gameplay section to drive and
assert the new contract. PlayActions remains delivered to the opponent (Uri
preserved, body now synthesized by PlayActionsHandler).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>