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/Editor/Ghost.Editor/Properties/Resources.Designer.cs

@@ -13,7 +13,7 @@ namespace Ghost.Editor.Properties {
     
     
     /// <summary>
-    ///   A strongly-typed resource class, for looking up localized strings, etc.
+    ///   A strongly-typed heap class, for looking up localized strings, etc.
     /// </summary>
     // This class was auto-generated by the StronglyTypedResourceBuilder
     // class via a tool like ResGen or Visual Studio.
@@ -48,7 +48,7 @@ namespace Ghost.Editor.Properties {
         
         /// <summary>
         ///   Overrides the current thread's CurrentUICulture property for all
-        ///   resource lookups using this strongly typed resource class.
+        ///   heap lookups using this strongly typed heap class.
         /// </summary>
         [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
         internal static global::System.Globalization.CultureInfo Culture {