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/RenderSystem.cs

@@ -264,8 +264,12 @@ internal class RenderSystem : IRenderSystem
                         var newSize = kvp.Value;
                         swapChain.Resize(newSize.x, newSize.y);
                     }
+
+                    _resizeRequest.Clear();
                 }
 
+                frameResource.CommandAllocator.Reset();
+
                 var r = _graphicsEngine.RenderFrame(frameResource.CommandAllocator);
                 if (r.IsFailure)
                 {