feat(net): D.2b-B B-Wire — InventoryRemoveObject (0x0024) parser

Top-level GameMessage (UIQueue), not a GameEvent. Server sends when an
object leaves the client's inventory view (sold / dropped / destroyed).
Layout: opcode(4) + guid(4) = 8 bytes — the smallest inventory wire.
3 tests: happy path, wrong opcode, truncated.

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

src/AcDream.Core.Net/Messages/InventoryRemoveObject.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Buffers.Binary;
+
+namespace AcDream.Core.Net.Messages;
+
+/// <summary>
+/// Inbound <c>InventoryRemoveObject (0x0024)</c> — a top-level GameMessage (UIQueue),
+/// NOT a GameEvent. The server tells the client an object left its inventory view
+/// (given away / sold / destroyed). The client drops it from object maintenance.
+///
+/// <para>Wire layout (ACE <c>GameMessageInventoryRemoveObject.cs</c>, size hint 8):</para>
+/// <code>
+///   u32 opcode = 0x0024
+///   u32 guid
+/// </code>
+/// </summary>
+public static class InventoryRemoveObject
+{
+    public const uint Opcode = 0x0024u;
+
+    public readonly record struct Parsed(uint Guid);
+
+    /// <summary>Parse a raw 0x0024 body. Returns null on opcode mismatch / truncation.</summary>
+    public static Parsed? TryParse(ReadOnlySpan<byte> body)
+    {
+        if (body.Length < 8) return null;           // 4 + 4
+        if (BinaryPrimitives.ReadUInt32LittleEndian(body) != Opcode) return null;
+        uint guid = BinaryPrimitives.ReadUInt32LittleEndian(body[4..]);
+        return new Parsed(guid);
+    }
+}

tests/AcDream.Core.Net.Tests/Messages/InventoryRemoveObjectTests.cs

@@ -0,0 +1,32 @@
+using System.Buffers.Binary;
+using AcDream.Core.Net.Messages;
+using Xunit;
+
+namespace AcDream.Core.Net.Tests.Messages;
+
+public sealed class InventoryRemoveObjectTests
+{
+    private static byte[] Build(uint guid, uint opcode = 0x0024u)
+    {
+        var b = new byte[8];
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(0), opcode);
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(4), guid);
+        return b;
+    }
+
+    [Fact]
+    public void TryParse_valid_returnsGuid()
+    {
+        var p = InventoryRemoveObject.TryParse(Build(0x50000A07u));
+        Assert.NotNull(p);
+        Assert.Equal(0x50000A07u, p!.Value.Guid);
+    }
+
+    [Fact]
+    public void TryParse_wrongOpcode_returnsNull()
+        => Assert.Null(InventoryRemoveObject.TryParse(Build(1, opcode: 0x0023u)));
+
+    [Fact]
+    public void TryParse_truncated_returnsNull()
+        => Assert.Null(InventoryRemoveObject.TryParse(new byte[7]));
+}