Initial commit: Item Interaction Ecosystem plugin (UE5.7)

Server-authoritative, data-driven item/inventory/interaction/carry/equipment/
world-slot/placement/crafting framework. 8 modules, compiles against UE 5.7.

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

Source/ItemDebug/Public/ItemDebugSubsystem.h

@@ -0,0 +1,24 @@
+// Copyright ExByte Studios. Item Interaction Ecosystem.
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Subsystems/WorldSubsystem.h"
+#include "ItemDebugSubsystem.generated.h"
+
+/**
+ * On-screen runtime debugger (section 29). Toggle with the console variable
+ * `ItemEco.DebugHUD 1`. Draws the local player's held item, current interaction
+ * target and the available interactions each frame. Read-only / client-local.
+ */
+UCLASS()
+class ITEMDEBUG_API UItemDebugSubsystem : public UTickableWorldSubsystem
+{
+	GENERATED_BODY()
+
+public:
+	//~ FTickableGameObject
+	virtual void Tick(float DeltaTime) override;
+	virtual TStatId GetStatId() const override;
+	virtual bool DoesSupportWorldType(const EWorldType::Type WorldType) const override;
+};