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.App/Net/LiveSessionCommandRouter.cs

@@ -33,6 +33,13 @@ internal sealed record LiveSessionCommandBindings(
     Action<uint> RemoveFriend,
     Action ClearFriends,
     Action RequestLegacyFriends,
+    // Secure trade (2026-08-14) — the CM_Trade senders.
+    Action<uint> OpenTradeNegotiations,
+    Action CloseTradeNegotiations,
+    Action<uint> AddToTrade,
+    Action<uint, bool, bool> AcceptTrade,
+    Action DeclineTrade,
+    Action ResetTrade,
     Action<bool, uint, string, uint> ModifyCharacterSquelch,
     Action<bool, string> ModifyAccountSquelch,
     Action<bool, uint> ModifyGlobalSquelch,
@@ -92,6 +99,17 @@ internal readonly record struct SetSingleCharacterOptionRuntimeCmd(
 internal readonly record struct SaveCharacterOptionsRuntimeCmd;
 internal readonly record struct AddFriendRuntimeCmd(string Name);
 internal readonly record struct RemoveFriendRuntimeCmd(uint CharacterId);
+
+// ── Secure trade (2026-08-14) ──────────────────────────────────────────────
+internal readonly record struct OpenTradeNegotiationsRuntimeCmd(uint PartnerGuid);
+internal readonly record struct CloseTradeNegotiationsRuntimeCmd;
+internal readonly record struct AddToTradeRuntimeCmd(uint ItemGuid);
+internal readonly record struct AcceptTradeRuntimeCmd(
+    uint PartnerGuid,
+    bool SelfAccepted,
+    bool PartnerAccepted);
+internal readonly record struct DeclineTradeRuntimeCmd;
+internal readonly record struct ResetTradeRuntimeCmd;
 internal readonly record struct ClearFriendsRuntimeCmd;
 internal readonly record struct RequestLegacyFriendsRuntimeCmd;
 internal readonly record struct ModifyCharacterSquelchRuntimeCmd(
@@ -210,6 +228,22 @@ internal sealed class LiveSessionCommandRouter : ILiveSessionCommandRouting
             _ => SendIfActive(bindings.SaveCharacterOptions));
         commands.Register<AddFriendRuntimeCmd>(
             command => SendIfActive(() => bindings.AddFriend(command.Name)));
+        commands.Register<OpenTradeNegotiationsRuntimeCmd>(
+            command => SendIfActive(() =>
+                bindings.OpenTradeNegotiations(command.PartnerGuid)));
+        commands.Register<CloseTradeNegotiationsRuntimeCmd>(
+            _ => SendIfActive(bindings.CloseTradeNegotiations));
+        commands.Register<AddToTradeRuntimeCmd>(
+            command => SendIfActive(() => bindings.AddToTrade(command.ItemGuid)));
+        commands.Register<AcceptTradeRuntimeCmd>(
+            command => SendIfActive(() => bindings.AcceptTrade(
+                command.PartnerGuid,
+                command.SelfAccepted,
+                command.PartnerAccepted)));
+        commands.Register<DeclineTradeRuntimeCmd>(
+            _ => SendIfActive(bindings.DeclineTrade));
+        commands.Register<ResetTradeRuntimeCmd>(
+            _ => SendIfActive(bindings.ResetTrade));
         commands.Register<RemoveFriendRuntimeCmd>(
             command => SendIfActive(() =>
                 bindings.RemoveFriend(command.CharacterId)));