Refactor GPU resource management and rendering pipeline

- Introduced `Handle<T>` and `Identifier<T>` for lightweight, strongly-typed resource identifiers.
- Replaced `BitSet` with `UnsafeBitSet` for improved performance and memory safety.
- Refactored `Mesh` and `Material` into `MeshClass` and `MaterialClass` for better GPU resource handling.
- Added `D3D12ResourceDatabase` to centralize GPU resource tracking and lifecycle management.
- Updated `D3D12ShaderCompiler` to load shaders from disk and dynamically populate constant buffers and textures.
- Enhanced `ICommandBuffer` with new upload operations for buffers and textures.
- Refactored `Vertex` struct for simplified memory layout and better performance.
- Updated `MeshBuilder` and rendering logic to align with new resource and shader structures.
- Added `BindlessDescriptor` support to `TextureHandle` and `BufferHandle`.
- Removed unused classes and performed general cleanup.
- Updated unit tests and demos to reflect the new architecture.

Ghost.Graphics/D3D12/CommandList.cs

@@ -33,7 +33,7 @@ public unsafe class CommandList
     /// </summary>
     /// <param name="mesh">The mesh to draw</param>
     /// <param name="material">The bindless material to use</param>
-    public void DrawMesh(Mesh mesh, Material material)
+    public void DrawMesh(MeshClass mesh, MaterialClass material)
     {
         // Bind the bindless material (sets up root signature, pipeline state, and descriptor heaps)
         material.Bind(this);
@@ -62,7 +62,7 @@ public unsafe class CommandList
         _commandList.Ptr->OMSetRenderTargets(1, pRtvHandle, false, pDsvHandle);
     }
 
-    public void ClearRenderTarget(RenderTexture renderTarget, Color16 color)
+    public void ClearRenderTarget(RenderTexture renderTarget, Color128 color)
     {
         renderTarget.ClearColor(this, color);
     }