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/RenderGraphNativePass.cs

@@ -0,0 +1,52 @@
+using Ghost.Core;
+
+namespace Ghost.RenderGraph.Concept;
+
+/// <summary>
+/// Represents a native render pass that can contain multiple merged logical passes.
+/// Maps to D3D12 BeginRenderPass/EndRenderPass or Vulkan vkCmdBeginRenderPass/vkCmdEndRenderPass.
+/// </summary>
+internal sealed class NativeRenderPass
+{
+    public int index;
+    
+    /// <summary>
+    /// Indices of logical passes merged into this native render pass.
+    /// </summary>
+    public readonly List<int> mergedPassIndices = new(4);
+    
+    /// <summary>
+    /// Color attachments shared across all merged passes.
+    /// </summary>
+    public RenderTargetInfo[] colorAttachments = new RenderTargetInfo[8];
+    public int colorAttachmentCount;
+    
+    /// <summary>
+    /// Depth-stencil attachment (optional).
+    /// </summary>
+    public DepthStencilInfo depthAttachment;
+    public bool hasDepthAttachment;
+    
+    /// <summary>
+    /// Range of logical passes included in this native pass.
+    /// </summary>
+    public int firstLogicalPass;
+    public int lastLogicalPass;
+    
+    /// <summary>
+    /// Whether UAV writes are allowed during this render pass.
+    /// </summary>
+    public bool allowUAVWrites;
+    
+    public void Reset()
+    {
+        index = -1;
+        mergedPassIndices.Clear();
+        colorAttachmentCount = 0;
+        hasDepthAttachment = false;
+        depthAttachment = default;
+        firstLogicalPass = int.MaxValue;
+        lastLogicalPass = -1;
+        allowUAVWrites = false;
+    }
+}