Mesh Optimizer: sibling StaticMesh duplicate remover (UE 5.7)

Editor plugin that detects geometrically-identical sibling StaticMeshes across a
level, rebases each placement onto one canonical mesh with a corrected transform
(W' = D * W, verified by exact vertex matching), and can collapse groups into HISM.
Native Slate tool panel + BlueprintCallable UOptimizerSubsystem.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Source/OptimizerEditor/Public/OptimizerEditorModule.h

@@ -0,0 +1,26 @@
+// Copyright IHY.
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Modules/ModuleInterface.h"
+
+/**
+ * Editor-only module for the Mesh Optimizer.
+ *
+ * Registers a Tools-menu entry + nomad tab hosting the native Slate panel (SOptimizerPanel),
+ * which drives UOptimizerSubsystem: scan level StaticMesh usage, group geometrically-identical
+ * "sibling" meshes, rebase every user onto one canonical mesh with a pivot/rotation-corrected
+ * transform, and optionally collapse the group into a HierarchicalInstancedStaticMesh.
+ */
+class FOptimizerEditorModule : public IModuleInterface
+{
+public:
+	virtual void StartupModule() override;
+	virtual void ShutdownModule() override;
+
+private:
+	void RegisterMenus();    // deferred via UToolMenus startup callback
+	TSharedRef<class SDockTab> SpawnPanelTab(const class FSpawnTabArgs& Args);
+
+	bool bTabRegistered = false;
+};