Source the played card's opponent-facing knownList[].cardId off the shadow engine
(SessionBattleEngine.PlayedCardId -> BattleCardBase.CardId), engine-first with the
wire-mined idx->cardId map as the fallback. PROVEN engine-resolved (each backed by a
HeadlessConductorTests PlayedCardId_* test): deck cards and receive-path substituted/
revealed tokens (engine seats the wire id at the wire idx).
PARTIAL retirement: the wire-mining bookkeeping (MineAddOps/MineChoicePicks/MineCopyTokens
+ Record*From) is KEPT as the load-bearing fallback. The choice/Discover, copy/clone and
cross-side (isSelf:0) token cases are NOT proven to resolve at a wire idx headless — the
autonomous token_draw path seats a chosen token at engine Index 0 (would collide with the
leader), and copy/cross-side aren't cheaply fixturable. Deleting their mining on faith
would silently corrupt opponent reveals, so it stays behind a TODO(M-HC-4f) gate.
- SessionBattleEngine.PlayedCardId: new accessor mirroring PlayedCardClan/Tribe.
- BuildPlayedCard: signature deckMap->explicit cardId; null on cardId==0 (no engine id AND
no mined/deck-map fallback).
- PlayActionsHandler: cardId = engine.PlayedCardId(seat, idx, fallback: mapped) ; mining retained.
- Tests: PlayedCardId_* (deck/substituted/degrade pass; choice-gap [Explicit] documents the
Index-0 finding). KnownListBuilder + CaptureConformance call-sites updated to new signature.
Full BattleNode suite 263/263 green; HeadlessConductorTests 27/27; drift clean; no Engine edits.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>