feat(resource): refactor heap management & suballocation

Major overhaul of GPU resource/heap management:
- Replace resource pooling and upload buffer logic with transient heap/page-based suballocation in ResourceManager.
- Add support for suballocation and heap flags/types, with D3D12 helpers.
- Remove ICommandBuffer.UploadBuffer/UploadTexture; add UpdateSubResources and CopyBuffer, move upload logic to RenderingContext.
- Refactor D3D12ResourceAllocator/Database for suballocation, heap flags, and mapping.
- Standardize on Handle<GPUBuffer> usage.
- Update meshlet/mesh utilities for new allocation handles and memory pools.
- Refactor RenderGraph and docs to use "heap" terminology.
- Use cpuFrame/gpuFrame consistently for frame sync.
- Add s2h.hlsl, s2h_3d.hlsl, s2h_scatter.hlsl shader debug libs.
- Miscellaneous fixes, cleanup, and dependency updates.

BREAKING CHANGE: Resource pooling and upload APIs replaced with new heap/page-based suballocation system. Update all buffer/texture creation and upload code to use new ResourceManager and ICommandBuffer methods.

src/Runtime/Ghost.Graphics.RHI/Common.cs

@@ -152,6 +152,19 @@ public record struct Vertex
     public float2 uv;
 }
 
+public struct ResourceRange
+{
+    public nuint Start
+    {
+        get; set;
+    }
+
+    public nuint End
+    {
+        get; set;
+    }
+}
+
 public readonly struct ShaderVariant;
 public readonly struct GraphicsPipeline;