feat(net): D.2b-B B-Wire — ParseViewContents (0x0196)

GameEvents.ParseViewContents parses the ViewContents GameEvent payload:
containerGuid + count + [guid, containerType]×count. Records
ViewContentsEntry and ViewContents added. 3 unit tests added in
GameEventsInventoryTests.cs (two-entry, zero-count, truncated).

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

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

@@ -358,6 +358,29 @@ public static class GameEvents
             BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(8)));
     }
 
+    /// <summary>0x0196 ViewContents: full contents list of a container you opened.
+    /// Layout (ACE GameEventViewContents.cs): containerGuid, count, [guid, containerType]×count.
+    /// Client consumer: ClientUISystem::OnViewContents (PackableList&lt;ContentProfile&gt;).</summary>
+    public readonly record struct ViewContentsEntry(uint Guid, uint ContainerType);
+    public readonly record struct ViewContents(uint ContainerGuid, System.Collections.Generic.IReadOnlyList<ViewContentsEntry> Items);
+
+    public static ViewContents? ParseViewContents(ReadOnlySpan<byte> payload)
+    {
+        if (payload.Length < 8) return null;
+        uint containerGuid = BinaryPrimitives.ReadUInt32LittleEndian(payload);
+        uint count = BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(4));
+        int pos = 8;
+        if ((long)payload.Length - pos < (long)count * 8) return null;
+        var items = new ViewContentsEntry[count];
+        for (int i = 0; i < count; i++)
+        {
+            uint guid = BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(pos)); pos += 4;
+            uint type = BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(pos)); pos += 4;
+            items[i] = new ViewContentsEntry(guid, type);
+        }
+        return new ViewContents(containerGuid, items);
+    }
+
     // ── Other small-payload events ──────────────────────────────────────────
 
     /// <summary>0x01C7 UseDone: the Use/UseWithTarget completion signal (WeenieError code).</summary>

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

@@ -0,0 +1,45 @@
+using System.Buffers.Binary;
+using AcDream.Core.Net.Messages;
+using Xunit;
+
+namespace AcDream.Core.Net.Tests.Messages;
+
+public sealed class GameEventsInventoryTests
+{
+    [Fact]
+    public void ParseViewContents_twoEntries_returnsContainerAndItems()
+    {
+        // containerGuid + count(2) + 2×{guid, containerType}
+        var b = new byte[4 + 4 + 2 * 8];
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(0), 0x500000C9u); // containerGuid
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(4), 2u);          // count
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(8), 0x50000A01u); // guid 1
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(12), 0u);         // type 1 (item)
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(16), 0x50000A02u);// guid 2
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(20), 1u);         // type 2 (container)
+
+        var p = GameEvents.ParseViewContents(b);
+        Assert.NotNull(p);
+        Assert.Equal(0x500000C9u, p!.Value.ContainerGuid);
+        Assert.Equal(2, p.Value.Items.Count);
+        Assert.Equal(0x50000A01u, p.Value.Items[0].Guid);
+        Assert.Equal(0u, p.Value.Items[0].ContainerType);
+        Assert.Equal(0x50000A02u, p.Value.Items[1].Guid);
+        Assert.Equal(1u, p.Value.Items[1].ContainerType);
+    }
+
+    [Fact]
+    public void ParseViewContents_zeroCount_returnsEmptyList()
+    {
+        var b = new byte[8];
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(0), 0x500000C9u);
+        BinaryPrimitives.WriteUInt32LittleEndian(b.AsSpan(4), 0u);
+        var p = GameEvents.ParseViewContents(b);
+        Assert.NotNull(p);
+        Assert.Empty(p!.Value.Items);
+    }
+
+    [Fact]
+    public void ParseViewContents_truncated_returnsNull()
+        => Assert.Null(GameEvents.ParseViewContents(new byte[4]));
+}