refactor(runtime): own inventory transaction state

Move the retail one-request-at-a-time gate, shared use busy references, external-container state, item mana, shortcuts, and desired-component snapshots into one Runtime-owned graph over J3's exact ClientObjectTable. Retained UI and session routing now borrow that owner; reset and shutdown preserve the existing order while failure/reentrancy tests protect the transaction boundary.

Co-authored-by: Codex <codex@openai.com>

tests/AcDream.App.Tests/Runtime/CurrentGameRuntimeAdapterTests.cs

@@ -511,6 +511,7 @@ public sealed class CurrentGameRuntimeAdapterTests
             EquippedChildren = noop,
             ExternalContainer = noop,
             InteractionAndSelection = noop,
+            InventoryTransactions = noop,
             SelectionPresentation = noop,
             ObjectTable = noop,
             Spellbook = noop,

tests/AcDream.App.Tests/Runtime/RuntimeInventoryOwnershipTests.cs

@@ -0,0 +1,97 @@
+namespace AcDream.App.Tests.Runtime;
+
+public sealed class RuntimeInventoryOwnershipTests
+{
+    [Fact]
+    public void ProductionConstructsOnlyTheRuntimeInventoryOwner()
+    {
+        string source = ReadSource("Rendering", "GameWindow.cs");
+
+        Assert.Contains(
+            "_runtimeInventory = new RuntimeInventoryState(_runtimeEntityObjects);",
+            source,
+            StringComparison.Ordinal);
+        Assert.DoesNotContain(
+            "new AcDream.Core.Items.ItemManaState",
+            source,
+            StringComparison.Ordinal);
+        Assert.DoesNotContain(
+            "new DesiredComponentSnapshotState",
+            source,
+            StringComparison.Ordinal);
+        Assert.DoesNotContain(
+            "new ShortcutSnapshotState",
+            source,
+            StringComparison.Ordinal);
+        Assert.DoesNotContain(
+            "new AcDream.Core.Items.ExternalContainerState",
+            source,
+            StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void UiSessionAndShutdownBorrowTheExactRuntimeOwner()
+    {
+        string ui = ReadSource(
+            "Composition",
+            "InteractionRetainedUiComposition.cs");
+        string session = ReadSource("Net", "LiveSessionRuntimeFactory.cs");
+        string shutdown = ReadSource("Rendering", "GameWindowLifetime.cs");
+
+        Assert.Contains(
+            "transactions: d.Inventory.Transactions",
+            ui,
+            StringComparison.Ordinal);
+        Assert.Contains(
+            "OnShortcuts: _domain.Inventory.Shortcuts.Replace",
+            session,
+            StringComparison.Ordinal);
+        Assert.Contains(
+            "_domain.Inventory.Transactions.CompleteUse(error)",
+            session,
+            StringComparison.Ordinal);
+        Assert.Contains(
+            "OnDesiredComponents: _domain.Inventory.DesiredComponents.Replace",
+            session,
+            StringComparison.Ordinal);
+        AssertAppearsInOrder(
+            shutdown,
+            "\"runtime inventory state\"",
+            "\"runtime entity/object lifetime\"");
+    }
+
+    private static string ReadSource(params string[] relative)
+    {
+        string root = FindRepositoryRoot();
+        return File.ReadAllText(Path.Combine(
+            [root, "src", "AcDream.App", .. relative]));
+    }
+
+    private static string FindRepositoryRoot()
+    {
+        var current = new DirectoryInfo(AppContext.BaseDirectory);
+        while (current is not null)
+        {
+            if (File.Exists(Path.Combine(current.FullName, "AcDream.slnx")))
+                return current.FullName;
+            current = current.Parent;
+        }
+        throw new DirectoryNotFoundException("AcDream.slnx was not found.");
+    }
+
+    private static void AssertAppearsInOrder(
+        string source,
+        params string[] fragments)
+    {
+        int cursor = 0;
+        foreach (string fragment in fragments)
+        {
+            int index = source.IndexOf(
+                fragment,
+                cursor,
+                StringComparison.Ordinal);
+            Assert.True(index >= 0, $"Missing source fragment: {fragment}");
+            cursor = index + fragment.Length;
+        }
+    }
+}