Refactor RenderGraph barrier/state tracking system

Major overhaul of resource barrier and state tracking in RenderGraph:
- Introduce ResourceBarrierData for explicit (layout, access, sync) tracking.
- Separate aliasing and transition barriers; explicit aliasing support.
- Remove BufferHint; infer buffer usage from BufferUsage flags.
- Update TextureAccess/BufferAccess to include usage requirements.
- Improve enums (BarrierSync, BarrierAccess, BarrierLayout) for D3D12 alignment.
- Update D3D12CommandBuffer to use new barrier data and error handling.
- Make D3D12DescriptorHeap a class; add ReleaseSampler to IResourceDatabase.
- Reset resource pools and aliasing managers each frame.
- Batch and flush barriers efficiently per pass.
- Update HLSL mesh shader macros to [NumThreads].
- Remove obsolete code and improve documentation.
This refactor improves correctness, extensibility, and prepares for advanced features.

Ghost.Graphics/RenderGraphModule/RenderGraphResourcePool.cs

@@ -168,7 +168,7 @@ internal sealed class RenderGraphResourceRegistry
         }
     }
 
-    public void BeginFrame()
+    public void Reset()
     {
         // Return all resources to pool
         for (var i = 0; i < _resources.Count; i++)
@@ -179,13 +179,30 @@ internal sealed class RenderGraphResourceRegistry
         _resources.Clear();
     }
 
-    public Identifier<RGTexture> ImportTexture(ref readonly TextureDesc desc, Handle<Texture> texture, string name)
+    public Identifier<RGTexture> ImportTexture(ref readonly TextureDesc desc, Handle<Texture> texture, string name,
+        Color128 clearColor, float clearDepth, byte clearStencil,
+        bool clearAtFirstUse, bool discardAtLastUse)
     {
         var resource = _pool.Rent<RenderGraphResource>();
         resource.name = name;
         resource.type = RenderGraphResourceType.Texture;
         resource.index = _resources.Count;
-        resource.rgTextureDesc = RGTextureDesc.FromTextureDesc(in desc);
+        resource.rgTextureDesc = new RGTextureDesc
+        {
+            sizeMode = RGTextureSizeMode.Absolute,
+            width = desc.Width,
+            height = desc.Height,
+            format = desc.Format,
+            clearColor = clearColor,
+            clearDepth = clearDepth,
+            clearStencil = clearStencil,
+            clearAtFirstUse = clearAtFirstUse,
+            discardAtLastUse = discardAtLastUse,
+            dimension = desc.Dimension,
+            mipLevels = desc.MipLevels,
+            slice = desc.Slice,
+            usage = desc.Usage
+        };
         resource.isImported = true;
         resource.backingResource = texture.AsResource();
         resource.resolvedWidth = desc.Width;