fix(overlays): avoid version-specific scene handle access

src/BazaarPlusPlus/Game/OverlayPanels/OverlayPanelHost.cs

@@ -15,7 +15,7 @@ internal sealed class OverlayPanelHost : MonoBehaviour
     private readonly OverlayLifecycleCore _core = new();
     private readonly OverlayPanelHostLogState _logState = new();
     private readonly List<OverlayPanelRegistration> _registrations = new();
-    private int _sceneTokenHandle;
+    private Scene _sceneTokenScene;
     private bool _sceneTokenLoaded;
     private string _sceneToken = string.Empty;
 
@@ -128,18 +128,18 @@ private void Unregister(string panelId)
     private bool ReadIsInCombat() =>
         _logState.ReadIsInCombat(static () => TheBazaar.Data.IsInCombat);
 
-    // name/path/buildIndex are fixed for a given scene handle, so the token string is rebuilt
-    // only when the active scene (or its loaded flag) actually changes.
+    // Compare Scene values, not Scene.handle: Unity 6 changed that getter's return type
+    // from int to SceneHandle. The equality operator's ABI is stable across both versions.
     private string GetSceneToken(Scene scene)
     {
         if (
             _sceneToken.Length != 0
-            && _sceneTokenHandle == scene.handle
+            && _sceneTokenScene == scene
             && _sceneTokenLoaded == scene.isLoaded
         )
             return _sceneToken;
 
-        _sceneTokenHandle = scene.handle;
+        _sceneTokenScene = scene;
         _sceneTokenLoaded = scene.isLoaded;
         _sceneToken = $"{scene.name}|{scene.path}|{scene.buildIndex}|{scene.isLoaded}";
         return _sceneToken;

src/BazaarPlusPlus/GameInterop/Scenes/ActiveSceneNameCache.cs

@@ -10,7 +10,7 @@ namespace BazaarPlusPlus.GameInterop.Scenes;
 /// </summary>
 internal static class ActiveSceneNameCache
 {
-    private static int _handle;
+    private static Scene _scene;
     private static bool _loaded;
     private static bool _hasName;
     private static string _name = string.Empty;
@@ -20,10 +20,10 @@ internal static string Current
         get
         {
             var scene = SceneManager.GetActiveScene();
-            if (_hasName && _handle == scene.handle && _loaded == scene.isLoaded)
+            if (_hasName && _scene == scene && _loaded == scene.isLoaded)
                 return _name;
 
-            _handle = scene.handle;
+            _scene = scene;
             _loaded = scene.isLoaded;
             _name = scene.name;
             _hasName = true;

tests/RuntimeIntegration.Tests/SceneRuntimeCompatibilityTests.cs

@@ -0,0 +1,34 @@
+using System.Reflection.Metadata;
+using System.Reflection.PortableExecutable;
+using Xunit;
+
+namespace RuntimeIntegration.Tests;
+
+public sealed class SceneRuntimeCompatibilityTests
+{
+    [Fact]
+    public void Compiled_mod_does_not_bind_to_the_version_specific_scene_handle_getter()
+    {
+        using var stream = File.OpenRead(
+            Path.Combine(AppContext.BaseDirectory, "BazaarPlusPlus.dll")
+        );
+        using var pe = new PEReader(stream);
+        var metadata = pe.GetMetadataReader();
+        var sceneMembers = new List<string>();
+        foreach (var handle in metadata.MemberReferences)
+        {
+            var member = metadata.GetMemberReference(handle);
+            if (member.Parent.Kind != HandleKind.TypeReference)
+                continue;
+            var type = metadata.GetTypeReference((TypeReferenceHandle)member.Parent);
+            if (
+                metadata.GetString(type.Namespace) == "UnityEngine.SceneManagement"
+                && metadata.GetString(type.Name) == "Scene"
+            )
+                sceneMembers.Add(metadata.GetString(member.Name));
+        }
+
+        Assert.DoesNotContain("get_handle", sceneMembers);
+        Assert.Contains("op_Equality", sceneMembers);
+    }
+}