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.Core/Handle.cs

@@ -1,9 +1,5 @@
 namespace Ghost.Core;
 
-public interface IHandleType;
-public interface IIdentifierType;
-public interface IKeyType;
-
 public readonly struct Handle<T> : IEquatable<Handle<T>>
 {
     public int ID
@@ -139,19 +135,19 @@ public readonly struct Identifier<T> : IEquatable<Identifier<T>>
     public static implicit operator Identifier<T>(int value) => new Identifier<T>(value);
 }
 
-public readonly struct Key<T>
+public readonly struct Key64<T> : IEquatable<Key64<T>>
 {
     public ulong Value
     {
         get;
     }
 
-    public Key(ulong value)
+    public Key64(ulong value)
     {
         Value = value;
     }
 
-    public static Key<T> Invalid => new(0);
+    public static Key64<T> Invalid => new(0);
 
     public bool IsValid => this != Invalid;
     public bool IsInvalid => this == Invalid;
@@ -161,28 +157,86 @@ public readonly struct Key<T>
         return Value.GetHashCode();
     }
 
-    public readonly override bool Equals(object? obj)
-    {
-        return obj is Key<T> id && Equals(id);
-    }
-
-    public readonly bool Equals(Key<T> other)
+    public readonly bool Equals(Key64<T> other)
     {
         return Value == other.Value;
     }
 
-    public readonly int CompareTo(Key<T> other)
+    public readonly int CompareTo(Key64<T> other)
     {
         return Value.CompareTo(other.Value);
     }
 
-    public static bool operator ==(Key<T> a, Key<T> b)
+    public readonly override bool Equals(object? obj)
+    {
+        return obj is Key64<T> id && Equals(id);
+    }
+
+    public override string ToString()
+    {
+        return Value.ToString("X16");
+    }
+
+    public static bool operator ==(Key64<T> a, Key64<T> b)
     {
         return a.Equals(b);
     }
 
-    public static bool operator !=(Key<T> a, Key<T> b)
+    public static bool operator !=(Key64<T> a, Key64<T> b)
     {
         return !a.Equals(b);
     }
 }
+
+public readonly struct Key128<T> : IEquatable<Key128<T>>
+{
+    public UInt128 Value
+    {
+        get;
+    }
+
+    public Key128(UInt128 value)
+    {
+        Value = value;
+    }
+
+    public static Key128<T> Invalid => new(0);
+
+    public bool IsValid => this != Invalid;
+    public bool IsInvalid => this == Invalid;
+
+    public readonly override int GetHashCode()
+    {
+        return Value.GetHashCode();
+    }
+
+    public readonly bool Equals(Key128<T> other)
+    {
+        return Value == other.Value;
+    }
+
+    public readonly int CompareTo(Key128<T> other)
+    {
+        return Value.CompareTo(other.Value);
+    }
+
+    public readonly override bool Equals(object? obj)
+    {
+        return obj is Key128<T> id && Equals(id);
+    }
+
+    public override string ToString()
+    {
+        return Value.ToString("X16");
+    }
+
+    public static bool operator ==(Key128<T> a, Key128<T> b)
+    {
+        return a.Equals(b);
+    }
+
+    public static bool operator !=(Key128<T> a, Key128<T> b)
+    {
+        return !a.Equals(b);
+    }
+}