Render graph: native pass merging & heap-based aliasing

Major architecture upgrade:
- Add native render pass merging (hardware pass grouping, load/store op inference)
- Implement heap-based aliasing for textures & buffers (D3D12-style)
- Unify resource model: buffers and textures in one registry
- Extend builder API for buffer creation/usage, access flags, hints
- Improve barrier/state tracking (buffer hints, indirect argument state)
- Update caching, hashing, and debug output for new model
- Add enums/structs: AttachmentLoadOp, StoreOp, BufferHint, etc.
- D3D12 backend: support named resources, temp upload buffers, correct heap usage
- Update docs, benchmarks, and project files for new features

Brings render graph closer to AAA engine standards, enabling efficient memory usage, lower driver overhead, and a more flexible API.

Ghost.Graphics/D3D12/D3D12DescriptorAllocator.cs

@@ -386,22 +386,22 @@ internal unsafe class D3D12DescriptorAllocator : IDisposable
     #region Utility Methods
 
     /// <summary>
-    /// Gets the RTV heap for binding to the command list.
+    /// Gets the RTV Heap for binding to the command list.
     /// </summary>
     public ID3D12DescriptorHeap* GetRTVHeap() => _rtvHeap.Heap;
 
     /// <summary>
-    /// Gets the DSV heap for binding to the command list.
+    /// Gets the DSV Heap for binding to the command list.
     /// </summary>
     public ID3D12DescriptorHeap* GetDSVHeap() => _dsvHeap.Heap;
 
     /// <summary>
-    /// Gets the CBV/SRV/UAV heap for binding to the command list.
+    /// Gets the CBV/SRV/UAV Heap for binding to the command list.
     /// </summary>
     public ID3D12DescriptorHeap* GetCbvSrvUavHeap() => _cbvSrvUavHeap.ShaderVisibleHeap;
 
     /// <summary>
-    /// Gets the sampler heap for binding to the command list.
+    /// Gets the sampler Heap for binding to the command list.
     /// </summary>
     public ID3D12DescriptorHeap* GetSamplerHeap() => _samplerHeap.ShaderVisibleHeap;