Refactor: variant-aware shader/material pipeline overhaul

Major architectural update to graphics/material/shader system:
- Introduced strongly-typed key structs (Key64/Key128) for passes, variants, and pipelines; removed legacy key types.
- Implemented robust hashing and key generation utilities for efficient variant and pipeline lookup/caching.
- Shader compiler now compiles/caches all keyword variants using new key system; includes handled as lists.
- Switched to push constant root signature for per-draw data; updated HLSL and C# codegen accordingly.
- Refactored Material, Shader, and Pass data structures for cache efficiency and variant support.
- Pipeline library and PSO management now use 128-bit keys and variant-specific caching.
- Replaced WorldNode with SceneNode in editor/scene graph; introduced ComponentManager for archetype/query management.
- Migrated math utilities to Misaki.HighPerformance.Mathematics; updated editor controls.
- Updated all HLSL and codegen for new buffer/push constant layouts and macros.
- Misc: project reference cleanup, D3D12 Work Graph support, doc updates, and code modernization.

Ghost.Engine/Core/Scene.cs

@@ -0,0 +1,41 @@
+using Ghost.Entities;
+
+namespace Ghost.Engine.Core;
+
+public partial class Scene
+{
+    private static short s_nextSceneID = 0;
+}
+
+public partial class Scene : IDisposable
+{
+    private readonly World _world;
+    private readonly short _id;
+
+    private bool _isDisposed;
+
+    public World World => _world;
+    public short ID => _id;
+
+    public Scene(World world)
+    {
+        _world = world;
+        _id = s_nextSceneID++;
+    }
+
+    ~Scene()
+    {
+        Dispose();
+    }
+
+    public void Dispose()
+    {
+        if (_isDisposed)
+        {
+            return;
+        }
+
+        _isDisposed = true;
+        GC.SuppressFinalize(this);
+    }
+}