build: VoxelForge compiles in Unreal 5.7 on Linux (L65); Linux-only Unreal trace timing fields

Linux UE builds failed on the Core wrapper module: the Linux-only PerModuleInline.gen.cpp saw Standalone/Compat
shadow headers instead of the engine's, and WITH_EDITOR was redefined under -Werror. Compat headers now forward
to the engine headers with include_next for generated Linux module TUs (canonical Core TUs opt into the Compat
definitions via CoreNamespacePreamble.h); CoreMinimal.h undefines WITH_EDITOR first. VoxelForgeCore.Build.cs
enables that forwarding and AVX2 on Linux only; VoxelForge.Build.cs disables Unity on Linux only. Portability:
std::int64_t consistently in VoxelContentManager.cpp; grouped &&/|| in VoxelRedefinedDensityField.cpp. Linux-only
trace fields split Core generateTile / mesh copy / RMC stream build. Standalone Clang and GCC whole-view hashes
are unchanged vs 3202193. The Unreal spawn trace is blocked by the owner's new assets (SW route sweep fails).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Source/VoxelForge/VoxelForge.Build.cs

@@ -7,6 +7,13 @@ public class VoxelForge : ModuleRules
 {
 	public VoxelForge(ReadOnlyTargetRules Target) : base(Target)
 	{
+		if (Target.Platform == UnrealTargetPlatform.Linux)
+		{
+			// Test translation units have independent anonymous-namespace helpers that collide in
+			// Linux Unity batches. Keep Linux compilation one source per TU; Windows remains unchanged.
+			bUseUnity = false;
+		}
+
 		// PCH = Precompiled Headers - speeds up compilation
 		// UseExplicitOrSharedPCHs is the modern recommended setting
 		PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;