feat(core): D.2b-B — ClientObjectTable.SumCarriedBurden (carried-Burden fallback)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

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

@@ -0,0 +1,32 @@
+using AcDream.Core.Items;
+using Xunit;
+
+namespace AcDream.Core.Tests.Items;
+
+public class ClientObjectTableBurdenTests
+{
+    private const uint Player = 0x50000001u;
+
+    [Fact]
+    public void SumCarriedBurden_sums_pack_sidebag_and_wielded_but_not_unrelated()
+    {
+        var t = new ClientObjectTable();
+        // loose pack item
+        t.AddOrUpdate(new ClientObject { ObjectId = 0xA, ContainerId = Player, Burden = 100 });
+        // side bag in pack
+        t.AddOrUpdate(new ClientObject { ObjectId = 0xB, ContainerId = Player, Burden = 50,
+            Type = ItemType.Container });
+        // item inside the side bag (2-deep)
+        t.AddOrUpdate(new ClientObject { ObjectId = 0xC, ContainerId = 0xB, Burden = 30 });
+        // wielded (ContainerId 0, WielderId = player)
+        t.AddOrUpdate(new ClientObject { ObjectId = 0xD, WielderId = Player, Burden = 200 });
+        // unrelated object in the world
+        t.AddOrUpdate(new ClientObject { ObjectId = 0xE, ContainerId = 0, Burden = 999 });
+
+        Assert.Equal(380, t.SumCarriedBurden(Player));   // 100+50+30+200
+    }
+
+    [Fact]
+    public void SumCarriedBurden_unknown_owner_is_zero()
+        => Assert.Equal(0, new ClientObjectTable().SumCarriedBurden(Player));
+}