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.RenderGraph.Concept/PassData.cs

@@ -25,6 +25,7 @@ public sealed class SSAOPassData : IPassData
     public Identifier<RGTexture> GBufferDepth;
     public Identifier<RGTexture> GBufferNormal;
     public Identifier<RGTexture> OutputSSAO;
+    public Identifier<RGBuffer> OutputSSAOBuffer;
 }
 
 public sealed class BloomDownsampleData : IPassData
@@ -39,6 +40,12 @@ public sealed class TAAPassData : IPassData
     public Identifier<RGTexture> OutputTAA;
 }
 
+public sealed class PostProcessingPassDataV1 : IPassData
+{
+    public Identifier<RGTexture> InputLighting;
+    public Identifier<RGTexture> OutputBackbuffer;
+}
+
 public sealed class PostProcessingPassDataV2 : IPassData
 {
     public Identifier<RGTexture> InputTAA;