GhostEngine Render Graph: major refactor & Unity RG ref

- Major architectural refactor for performance, extensibility, and feature completeness: resource pooling, pass culling, aliasing, and compilation caching.
- Introduces type-safe builder and context APIs, blackboard pattern, and unified resource management.
- Adds detailed documentation and cleans up obsolete files and APIs.
- Includes (commented) Unity Render Graph source for reference; not compiled, for parity and future extension.

Ghost.RenderGraph.Concept/Ghost.RenderGraph.Concept.csproj

@@ -5,14 +5,19 @@
     <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+    <DefineConstants>$(DefineConstants);PROFILING</DefineConstants>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
+    <DefineConstants>$(DefineConstants);PROFILING</DefineConstants>
   </PropertyGroup>
 
   <ItemGroup>
     <ProjectReference Include="..\Ghost.Core\Ghost.Core.csproj" />
   </ItemGroup>
 
-  <ItemGroup>
-    <Folder Include="New\" />
-  </ItemGroup>
-
 </Project>