Removes the Scripted enum value, the bot's client-shaped emissions (BuildClient*),
the canned opponent turn (BuildOpponent*), and OpponentTurnStartSpin. The shared
server-frame builders (Matched/BattleStart/Deal/Swap/Ready + ComputeHandAfterSwap)
and OpponentJudgeSpin (Bot mode) stay.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Phase 1 foundation types for the v2 broker architecture. Nothing uses
them yet; they land alongside the existing v1.2 code so subsequent
tasks can extract the participant interface and impls.