refactor(battlenode): engine-first token identity (cardId); keep wire-mining fallback (M-HC-4f, partial)

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>

SVSim.UnitTests/BattleNode/Integration/CaptureConformanceTests.cs

@@ -282,7 +282,7 @@ public class CaptureConformanceTests
                 }
             }
         };
-        var entry = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.BuildPlayedCard(deckMap, 17, orderList);
+        var entry = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.BuildPlayedCard(17, deckMap[17], orderList);
         Assert.That(entry, Is.Not.Null);
 
         var body = new SVSim.BattleNode.Protocol.Bodies.PlayActionsBroadcastBody(
@@ -333,7 +333,7 @@ public class CaptureConformanceTests
             new Dictionary<string, object?> { ["move"] = new Dictionary<string, object?>
                 { ["idx"] = new List<object?> { 38L }, ["isSelf"] = 1L, ["from"] = 10L, ["to"] = 20L } },
         };
-        var entry = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.BuildPlayedCard(map, 38, playOrderList);
+        var entry = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.BuildPlayedCard(38, map[38], playOrderList);
         Assert.That(entry, Is.Not.Null, "the mined token resolves to a knownList entry");
 
         var body = new SVSim.BattleNode.Protocol.Bodies.PlayActionsBroadcastBody(
@@ -456,7 +456,7 @@ public class CaptureConformanceTests
             }
         };
 
-        var played = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.BuildPlayedCard(deckMap, 18, orderList);
+        var played = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.BuildPlayedCard(18, deckMap[18], orderList);
         var keyActionOut = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.StripKeyActionForOpponent(keyActionIn);
         var body = new SVSim.BattleNode.Protocol.Bodies.PlayActionsBroadcastBody(
             PlayIdx: 18, Type: 30, KnownList: new[] { played! }, OppoTargetList: null, KeyAction: keyActionOut);
@@ -520,7 +520,7 @@ public class CaptureConformanceTests
             new Dictionary<string, object?> { ["move"] = new Dictionary<string, object?>
                 { ["idx"] = new List<object?> { 46L }, ["isSelf"] = 1L, ["from"] = 10L, ["to"] = 20L } },
         };
-        var entry = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.BuildPlayedCard(map, 46, playOrderList);
+        var entry = SVSim.BattleNode.Sessions.Dispatch.KnownListBuilder.BuildPlayedCard(46, map[46], playOrderList);
         Assert.That(entry, Is.Not.Null, "the mined choice pick resolves to a knownList entry");
 
         var body = new SVSim.BattleNode.Protocol.Bodies.PlayActionsBroadcastBody(

SVSim.UnitTests/BattleNode/Integration/HeadlessConductorTests.cs

@@ -1285,6 +1285,117 @@ public class HeadlessConductorTests
         Assert.That(body.KnownList[0].Tribe, Is.Not.EqualTo("0"), "non-vacuity: tribe must not be the \"0\" default");
     }
 
+    // === M-HC-4f: engine-resolved token identity (cardId) on the knownList =========================
+    //
+    // The opponent-facing knownList[].cardId is now ENGINE-sourced (PlayActionsHandler reads
+    // SessionBattleEngine.PlayedCardId off the resolved card). These tests prove the engine carries the TRUE
+    // id for each token case the retired wire-mining used to handle — deck card, generated/substituted token,
+    // and choice/Discover token — so the wire-mined idx→cardId bookkeeping for the PLAYED card is redundant.
+    // (The deck-map remains as the non-engine-session fallback.)
+
+    [Test]
+    public void PlayedCardId_reads_engine_resolved_deck_card_id()
+    {
+        // BASELINE (proves the read mechanism): a plain DECK card. Play it and assert PlayedCardId returns the
+        // seeded deck id — the same value the deck-map fallback would have supplied, read off the engine.
+        var deck = new List<long> { NodeNativeBattleHarness.VanillaFollowerId };
+        deck.AddRange(NodeNativeBattleHarness.DefaultDeck());
+        deck = deck.GetRange(0, 30);
+        using var harness = NodeNativeBattleHarness.Create(seatADeck: deck);
+
+        Assert.That(harness.Push(NetworkBattleUri.Deal, DealBody(), isPlayerSeat: true).Accepted, Is.True, "Deal");
+        int playIdx = harness.PlayerHandCardIndex(0);
+        long dealtId = harness.HandCardId(playerSeat: true, handPos: 0); // the engine-seated deck identity at this idx
+        Assert.That(harness.Push(NetworkBattleUri.PlayActions, PlayBody(playIdx), isPlayerSeat: true).Accepted,
+            Is.True, "deck-card play");
+
+        Assert.That(harness.PlayedCardId(playerSeat: true, idx: playIdx), Is.EqualTo(dealtId),
+            "PlayedCardId must return the engine-resolved deck card identity");
+        // Cross-check against the deck-map (the retired path's source) so we KNOW the engine read is equivalent
+        // for a deck card — the behavior-preserving guarantee for the common case.
+        Assert.That(dealtId, Is.EqualTo(harness.SeatADeck[playIdx - 1]),
+            "the dealt id equals the node's shuffled deck-map id at this idx (engine read == deck-map fallback)");
+    }
+
+    [Test]
+    public void PlayedCardId_degrades_to_fallback_for_unknown_idx()
+    {
+        // Graceful degradation (mirrors PlayedCardCost_degrades_*): a non-engine session / unmapped idx returns
+        // the caller's fallback — the deck-map id the handler hands in — never crashing.
+        using var harness = NodeNativeBattleHarness.Create();
+        Assert.That(harness.PlayedCardId(playerSeat: true, idx: 9999, fallback: 424242L), Is.EqualTo(424242L));
+    }
+
+    [Test]
+    public void PlayedCardId_reads_substituted_token_identity_off_the_board()
+    {
+        // GENERATED/SUBSTITUTED TOKEN: M-HC-2 proved a reveal seats the WIRE cardId (overriding the seeded id)
+        // via CreateActualCard. This proves PlayedCardId then reads that TRUE id off the resolved card — so a
+        // later play of a generated token reveals its real identity engine-sourced, NOT the wire-mined map.
+        // Reuse the substitution fixture: seat B's deck is uniformly Z; the reveal substitutes W at idx 1.
+        const long Z = NodeNativeBattleHarness.VanillaFollowerId;       // seeded identity
+        const long W = NodeNativeBattleHarness.AltVanillaFollowerId;    // the wire (revealed) identity
+        var seatBDeck = Enumerable.Repeat(Z, 30).ToList();
+        using var harness = NodeNativeBattleHarness.Create(seatBDeck: seatBDeck);
+
+        Assert.That(harness.Push(NetworkBattleUri.Deal, DealBody(), isPlayerSeat: true).Accepted, Is.True, "Deal");
+        Assert.That(harness.Push(NetworkBattleUri.Swap, SwapBody(), isPlayerSeat: true).Accepted, Is.True, "Swap");
+        Assert.That(harness.Push(NetworkBattleUri.Ready, ReadyBody(), isPlayerSeat: true).Accepted, Is.True, "Ready");
+        Assert.That(harness.Push(NetworkBattleUri.TurnStart, TurnStartBody(), isPlayerSeat: true).Accepted, Is.True, "turn1 TurnStart");
+        Assert.That(harness.Push(NetworkBattleUri.TurnEnd, TurnEndBody(), isPlayerSeat: true).Accepted, Is.True, "turn1 TurnEnd");
+        Assert.That(harness.Push(NetworkBattleUri.TurnStart, TurnStartBody(), isPlayerSeat: false).Accepted, Is.True, "turn2 TurnStart (B)");
+
+        Assert.That(harness.Push(NetworkBattleUri.PlayActions, RevealPlayBody(idx: 1, cardId: W), isPlayerSeat: false).Accepted,
+            Is.True, "seat B reveal-play");
+        int boardIdx = harness.InPlayCardIndex(playerSeat: false, boardPos: 0);
+
+        // THE assertion: PlayedCardId reads the SUBSTITUTED wire id W off the resolved board card, not the seeded Z.
+        Assert.That(harness.PlayedCardId(playerSeat: false, idx: boardIdx), Is.EqualTo(W),
+            "PlayedCardId must read the engine-seated (substituted) wire cardId, not the seeded deck id");
+        Assert.That(harness.PlayedCardId(playerSeat: false, idx: boardIdx), Is.Not.EqualTo(Z),
+            "non-vacuity: the read is the wire id, NOT the seeded identity at that idx");
+    }
+
+    [Test]
+    [Explicit("M-HC-4f UNPROVEN case: the engine's autonomous token_draw seats the chosen token at engine " +
+              "Index 0 headless (NOT a wire idx past the deck), so PlayedCardId cannot address it by idx — it " +
+              "would collide with the leader (also Index 0). This test DOCUMENTS the gap that keeps " +
+              "MineChoicePicks wire-mining alive (see TODO(M-HC-4f) in PlayActionsHandler). Run explicitly to " +
+              "re-verify the gap; it asserts the FINDING (Index 0), not a passing engine read.")]
+    public void PlayedCardId_choice_token_seats_at_index_zero_headless_GAP()
+    {
+        // CHOICE/Discover TOKEN — the case the engine does NOT resolve at a wire idx headless. Playing the choice
+        // card (127011010) and choosing token B (120011010) lands it in hand with the correct IDENTITY, but at
+        // engine Index 0 (the autonomous token_draw skill path, not the wire add-op/replace path the relay uses).
+        // PlayedCardId(seat, 0) would therefore read the LEADER (Index 0), not the token — so the engine cannot
+        // replace MineChoicePicks for this case. (In a real relay the token rides a wire add op that seats a dummy
+        // at a non-zero idx, then a replace substitutes the real id there — a path not reproducible cheaply here.)
+        var seatADeck = Enumerable.Repeat(NodeNativeBattleHarness.ChoiceCardId, 30).ToList();
+        using var harness = NodeNativeBattleHarness.Create(seatADeck: seatADeck);
+
+        Assert.That(harness.Push(NetworkBattleUri.Deal, DealBody(), isPlayerSeat: true).Accepted, Is.True, "Deal");
+        Assert.That(harness.Push(NetworkBattleUri.Swap, SwapBody(), isPlayerSeat: true).Accepted, Is.True, "Swap");
+        Assert.That(harness.Push(NetworkBattleUri.Ready, ReadyBody(), isPlayerSeat: true).Accepted, Is.True, "Ready");
+        Assert.That(harness.Push(NetworkBattleUri.TurnStart, TurnStartBody(), isPlayerSeat: true).Accepted, Is.True, "turn1 TurnStart");
+
+        int choiceIdx = harness.HandCardIndex(playerSeat: true, handPos: 0);
+        const long chosen = NodeNativeBattleHarness.ChoiceTokenB; // 120011010
+        Assert.That(harness.Push(NetworkBattleUri.PlayActions,
+                NodeNativeBattleHarness.ChoicePlayBody(choiceIdx, NodeNativeBattleHarness.ChoiceCardId, chosen),
+                isPlayerSeat: true).Accepted,
+            Is.True, "choice play (chose token B)");
+
+        // The chosen token IS in hand with the right identity (M-HC-4c proved this) ...
+        int tokenIdx = -1;
+        for (int i = 0; i < harness.HandCount(playerSeat: true); i++)
+            if (harness.HandCardId(playerSeat: true, i) == (int)chosen) { tokenIdx = harness.HandCardIndex(playerSeat: true, i); break; }
+        Assert.That(tokenIdx, Is.GreaterThanOrEqualTo(0), "the chosen token (B) must be in seat A's hand");
+
+        // ... but its engine Index is 0 — the documented gap. PlayedCardId(seat, 0) reads the leader, not the token.
+        Assert.That(tokenIdx, Is.EqualTo(0),
+            "FINDING: the autonomous token_draw seats the chosen token at engine Index 0 headless — not addressable by a wire idx");
+    }
+
     // The hand POSITION (0-based) of the seat-A hand card with the given engine Index, or -1. Lets a test
     // re-derive a HandCardId(seat, pos) lookup from an engine Index it already located by identity.
     private static int FindHandPosByEngineIdx(NodeNativeBattleHarness harness, int engineIdx)

SVSim.UnitTests/BattleNode/Integration/NodeNativeBattleHarness.cs

@@ -242,6 +242,12 @@ internal sealed class NodeNativeBattleHarness : IDisposable
     public int DeckCount(bool playerSeat) => Engine.DeckCount(playerSeat);
     public int Turn(bool playerSeat) => Engine.Turn(playerSeat);
 
+    /// <summary>The engine-resolved wire <c>cardId</c> of the card at engine <paramref name="idx"/> on the
+    /// given seat (M-HC-4f). Pass-through to <c>SessionBattleEngine.PlayedCardId</c> — the TRUE id the engine
+    /// seated (deck id / token id / chosen-token id / copied id), the value the handler now sources for the
+    /// opponent-facing knownList instead of the wire-mined map.</summary>
+    public long PlayedCardId(bool playerSeat, int idx, long fallback = 0) => Engine.PlayedCardId(playerSeat, idx, fallback);
+
     /// <summary>The engine Index of seat A's hand card at <paramref name="handPos"/> (the playIdx a
     /// Play frame would carry to play it).</summary>
     public int PlayerHandCardIndex(int handPos) => Engine.HandCardIndex(playerSeat: true, handPos);