feat: secure trade with other players - wire, RuntimeTradeState, the

authored gmSecureTradeUI window, and both retail open paths

Three-lane research first (docs/research/2026-08-14-trade-lane{A,B,C}):
retail gmSecureTradeUI decode, the byte-exact ACE/decomp/holtburger
three-way wire agreement, and the acdream seam map (which found both
open paths ALREADY classified by the ported policy - OpenSecureTrade on
Use-a-player, StartSecureTrade on drag-item-onto-player with the
DragItemOnPlayerOpensSecureTrade option - dead-ending at a stub toast).

- Core.Net: TradeRequests builders (0x1F6-0x204, retail's CM_Trade
  senders byte-checked against ACE's readers; the ACE-discarded
  AcceptTrade echo carries zero-count item lists - AD-94), corrected +
  completed inbound parsers (0x1FD-0x208; the old AddToTrade parser
  missed the SIDE dword, TradeFailure missed the reason), delegate-hole
  registrars, six WorldSession sends. 10 golden-byte tests.
- Runtime: RuntimeTradeState, the third sibling J-owner (fellowship/
  allegiance shape): session-scoped, clears at generation reset (new
  stage Trade=14), staged teardown stage 11 (Identity/EntityObjects
  shift 12/13, TeardownStageCount 14 - the FA2-era per-stage-flag test
  caught the mapping exactly as designed), combined ownership ledger,
  event routing with ACE's wrong-initiator RegisterTrade landmine
  honored (partner = whichever guid is not mine). 7 conformance tests.
- App: SecureTradeUiController binds the dedicated authored LayoutDesc
  0x2100000D (root 0x1000007A - gmSecureTradeUI::PostInit's exact ids):
  partner name/status/count/grid, the authored 'Trade' accept toggle
  (accept <-> decline withdraw), 'Clear All' (ACE clears BOTH sides -
  surfaced honestly), the X close, drop-on-your-grid staging, per-mode
  accept cues (partner icon's authored Highlight state + Trade button
  Selected latch). Mounted via the vendor recipe (nine-slice chrome,
  hidden until RegisterTrade). ItemInteractionController's two policy
  arms now raise SecureTradeRequested instead of the stub toast; the
  drag path queues the dragged item until the window registers
  (ClientTradeSystem::AttemptToTradeItem @0x0056DF80's shape).

Register: AD-94 (accept-echo zero-count lists), AD-95 (numeric-only
count texts pending template verification).

Suites: App 4,990/3, Core.Net 905, Runtime 1,626 - all green. The
panel itself is user-gate acceptance (two-client connected trade), the
#372-class lesson: fixture-green alone is not acceptance for a mount.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.Runtime/Session/LiveSessionEventRouter.cs

@@ -85,7 +85,10 @@ public sealed record LiveSocialSessionBindings(
     // compiles unchanged (docs/research/2026-08-11-fa-acdream-seams.md
     // §2.4 — "the established compatibility convention").
     RuntimeFellowshipState? Fellowship = null,
-    RuntimeAllegianceState? Allegiance = null);
+    RuntimeAllegianceState? Allegiance = null,
+    // Secure trade (2026-08-14): the third sibling J-owner, same
+    // trailing/optional compatibility convention.
+    RuntimeTradeState? Trade = null);
 
 /// <summary>
 /// Owns every inbound subscription for one exact live session. Domain state
@@ -281,6 +284,36 @@ public sealed class LiveSessionEventRouter : ILiveSessionEventRouting
                     ? notice => allegianceLogin.ApplyLoginNotification(
                         notice.CharacterGuid,
                         notice.IsLoggedIn)
+                    : null,
+                // Secure trade (2026-08-14): same conditional delegate-hole
+                // discipline. Self-vs-partner comparisons use the exact
+                // player guid the fellowship holes above already borrow.
+                onTradeRegister: social.Trade is { } tradeRegister
+                    ? update => tradeRegister.ApplyRegister(update, inventory.PlayerGuid())
+                    : null,
+                onTradeClose: social.Trade is { } tradeClose
+                    ? _ => tradeClose.ApplyClose()
+                    : null,
+                onTradeAdd: social.Trade is { } tradeAdd
+                    ? tradeAdd.ApplyAdd
+                    : null,
+                onTradeRemove: social.Trade is { } tradeRemove
+                    ? tradeRemove.ApplyRemove
+                    : null,
+                onTradeAccept: social.Trade is { } tradeAccept
+                    ? whoAccepted => tradeAccept.ApplyAccept(whoAccepted, inventory.PlayerGuid())
+                    : null,
+                onTradeDecline: social.Trade is { } tradeDecline
+                    ? whoDeclined => tradeDecline.ApplyDecline(whoDeclined, inventory.PlayerGuid())
+                    : null,
+                onTradeReset: social.Trade is { } tradeReset
+                    ? _ => tradeReset.ApplyReset()
+                    : null,
+                onTradeFailure: social.Trade is { } tradeFailure
+                    ? tradeFailure.ApplyFailure
+                    : null,
+                onTradeClearAcceptance: social.Trade is { } tradeClear
+                    ? tradeClear.ApplyClearAcceptance
                     : null));
             ConstructionCheckpoint();