fix(client): restore retail interaction parity

Harden keyboard and camera routing, inventory and vendor interactions, chat/emotes, relog portal flow, and paperdoll rendering. Add retail research, connected gate coverage, and release-gate validation.

tests/AcDream.Core.Tests/Items/InventoryContainerPlacementPolicyTests.cs

@@ -0,0 +1,76 @@
+using AcDream.Core.Items;
+
+namespace AcDream.Core.Tests.Items;
+
+public sealed class InventoryContainerPlacementPolicyTests
+{
+    private const uint Player = 0x50000001u;
+
+    [Fact]
+    public void FullItemCapacityRejectsNewItemButAllowsReorder()
+    {
+        var objects = new ClientObjectTable();
+        objects.AddOrUpdate(new ClientObject
+        {
+            ObjectId = Player,
+            Name = "Player",
+            ItemsCapacity = 1,
+            ContainersCapacity = 7,
+        });
+        objects.AddOrUpdate(new ClientObject { ObjectId = 2u });
+        objects.MoveItem(2u, Player, 0);
+        objects.AddOrUpdate(new ClientObject { ObjectId = 3u });
+
+        Assert.Equal(
+            InventoryContainerPlacementRejection.ItemCapacityFull,
+            InventoryContainerPlacementPolicy.Evaluate(objects, 3u, Player, Player));
+        Assert.Equal(
+            InventoryContainerPlacementRejection.None,
+            InventoryContainerPlacementPolicy.Evaluate(objects, 2u, Player, Player));
+    }
+
+    [Fact]
+    public void ContainerCycleAndTradeAreRejected()
+    {
+        var objects = new ClientObjectTable();
+        objects.AddOrUpdate(new ClientObject
+        {
+            ObjectId = 10u, Type = ItemType.Container, ItemsCapacity = 24,
+        });
+        objects.AddOrUpdate(new ClientObject
+        {
+            ObjectId = 11u, Type = ItemType.Container, ItemsCapacity = 24,
+        });
+        objects.MoveItem(11u, 10u, 0);
+
+        Assert.Equal(
+            InventoryContainerPlacementRejection.RecursiveContainment,
+            InventoryContainerPlacementPolicy.Evaluate(objects, 10u, 11u, Player));
+
+        objects.Get(10u)!.TradeState = 1;
+        Assert.Equal(
+            InventoryContainerPlacementRejection.SourceBeingTraded,
+            InventoryContainerPlacementPolicy.Evaluate(objects, 10u, Player, Player));
+    }
+
+    [Fact]
+    public void FullMessageMatchesRetailContainerTypeBranches()
+    {
+        var player = new ClientObject { ObjectId = Player, Name = "Backpack" };
+        var bag = new ClientObject { ObjectId = 2u, Name = "Pack" };
+        Assert.Equal(
+            "Backpack is completely full!",
+            InventoryContainerPlacementPolicy.ComposeClientLocal(
+                InventoryContainerPlacementRejection.ItemCapacityFull,
+                null,
+                player,
+                Player));
+        Assert.Equal(
+            "The Pack can fit no more containers!",
+            InventoryContainerPlacementPolicy.ComposeClientLocal(
+                InventoryContainerPlacementRejection.ContainerCapacityFull,
+                null,
+                bag,
+                Player));
+    }
+}