test(battlenode): N1 shadow replay tracks captured battle state (Phase 2 N1)

Full single-client capture replay (cl1 send=player seat, receive=opponent seat,
ts-ordered) ingests end-to-end: 33 frames, 0 rejects, 0 invariant violations at
turn boundaries (leader life/PP/board/hand).

Headless gaps filled per playbook (no Engine/ drift):
- IsRecovery=true after construction: the engine's own headless replay mode gates
  the live view/UI layer off (BattleUIContainer, turn-control UI, VFX waits) while
  keeping the live NetworkBattleReceiver (ND4) and authoritative state.
- Seed ToolboxGame.RealTimeNetworkAgent, BattleUIContainer, _backGround, and
  per-player NullPlayerEmotion no-ops the receive/turn cycle dereferences.
- _IfaceImpl.g.cs (shim, not Engine/): BattleCardView.BattleCardIconAnimations
  returns a lazy non-null no-op so the opponent card-reveal icon-init (deferred
  VFX) doesn't NRE.
- HeadlessCardMaster.Load made cumulative: it replaced the global CardMaster each
  call, so a Load(deck) evicted the oracle card set and broke tests run after.

Adds board-state accessors (LeaderLife/Pp/HandCount/BoardCount) and CaptureReplay
ts ordering.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SVSim.BattleEngine.Tests/SessionEngine/CaptureReplay.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Text.Json;
@@ -8,7 +9,7 @@ using SVSim.BattleNode.Protocol;
 
 namespace SVSim.BattleEngine.Tests.SessionEngine
 {
-    internal sealed record CapturedFrame(string Direction, string Uri, MsgEnvelope Env, string RawBody);
+    internal sealed record CapturedFrame(DateTime Ts, string Direction, string Uri, MsgEnvelope Env, string RawBody);
 
     /// <summary>Parses a battle_test ndjson capture into MsgEnvelopes the engine can ingest.
     ///
@@ -29,6 +30,9 @@ namespace SVSim.BattleEngine.Tests.SessionEngine
                 using var doc = JsonDocument.Parse(line);
                 var root = doc.RootElement;
                 var direction = root.TryGetProperty("direction", out var dEl) ? dEl.GetString() ?? "" : "";
+                var ts = root.TryGetProperty("ts", out var tsEl) && tsEl.ValueKind == JsonValueKind.String
+                    ? DateTime.Parse(tsEl.GetString()!, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind)
+                    : default;
                 if (!root.TryGetProperty("body", out var bodyEl) || bodyEl.ValueKind != JsonValueKind.Object)
                     continue;
 
@@ -50,7 +54,7 @@ namespace SVSim.BattleEngine.Tests.SessionEngine
                 MsgEnvelope env;
                 try { env = MsgEnvelope.FromJson(normalized); }
                 catch { continue; } // out-of-model / unparseable line
-                frames.Add(new CapturedFrame(direction, uri, env, normalized));
+                frames.Add(new CapturedFrame(ts, direction, uri, env, normalized));
             }
             return frames;
         }