Unified, portable Unreal Engine MCP system plugin

Merge of the two project copies into one self-contained plugin (the superset:
variable_op + variables.py, full pcg_op runtime/declarative/preset ops, the
CreateWidgetFloatAnimation widget tool, and full Voxel graph authoring).

Made fully project- and machine-agnostic — no hardcoded paths:
- New src/projectPaths.js auto-detects the host .uproject (walk-up), project
  name, Editor build target, log file, and engine install (EngineAssociation
  via launcher manifest/registry, else installed-engine scan). All overridable
  via UE_* env vars.
- Rewired buildOrchestrator/insights/launcher/insightsExporter/server.js and the
  Python workers (cpp_scaffold, live_coding, apply_graph, console) off the old
  C:/Github/ihy, IHY*, E:/UE_Versions and UE_5.7 literals onto the resolver.
- Voxel made optional: Build.cs auto-detects the Voxel plugin (env
  UE_MCP_WITH_VOXEL override) and the C++ compiles to stubs under WITH_MCP_VOXEL,
  so the module builds in projects without Voxel; .uplugin marks Voxel optional.
- De-branded the agent-gateway and docs; scrubbed a leaked API key; excluded
  node_modules/Binaries/Intermediate/__pycache__/secrets from the repo.

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

Source/UEBlueprintMCPEditor/Public/MCPVoxelGraphLibrary.h

@@ -0,0 +1,69 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Kismet/BlueprintFunctionLibrary.h"
+#include "MCPVoxelGraphLibrary.generated.h"
+
+class UEdGraph;
+
+UCLASS()
+class UEBLUEPRINTMCPEDITOR_API UMCPVoxelGraphLibrary : public UBlueprintFunctionLibrary
+{
+    GENERATED_BODY()
+
+public:
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static bool IsVoxelGraphAsset(UObject* Asset);
+
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString ListTerminalGraphsJson(UObject* Asset);
+
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static UEdGraph* FindTerminalEdGraph(UObject* Asset, const FString& Terminal);
+
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString DumpTerminalGraphJson(UObject* Asset, const FString& Terminal);
+
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString GetSelectedNodesJson(UObject* Asset, const FString& Terminal);
+
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString SpawnCommentNode(UEdGraph* Graph, FVector2D Position, FVector2D Size, const FString& Comment, FLinearColor Color);
+
+    // Returns a JSON catalogue of every spawnable Voxel node (struct nodes + function-library nodes).
+    // Filter is an optional case-insensitive substring matched against id / display name / category.
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString ListNodeTypesJson(const FString& Filter, int32 Limit);
+
+    // Spawns a functional Voxel node (UVoxelGraphNode_Struct) identified by NodeId
+    // (struct name, struct path, display name, or "Library.Function" for function nodes).
+    // Returns the new node GUID as string, or empty on failure.
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString SpawnStructNode(UEdGraph* Graph, const FString& NodeId, FVector2D Position);
+
+    // Registers a graph property and returns its new GUID as JSON {ok, guid, name, type}.
+    // Kind: "parameter" (graph parameter), "input"/"output" (function in/out), "local" (local variable).
+    // TypeStr: float|double|int|bool|vector2d|vector|color|name (defaults to float).
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString AddGraphPropertyJson(UObject* Asset, const FString& Terminal, const FString& Kind, const FString& Name, const FString& TypeStr, const FString& Category);
+
+    // Lists graph properties of the given Kind as JSON {ok, properties:[{guid,name,type,category}]}.
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString ListGraphPropertiesJson(UObject* Asset, const FString& Terminal, const FString& Kind);
+
+    // Spawns a usage node for an existing property (Ref = guid or name). bDeclaration only matters
+    // for Kind "local" (declaration vs usage). Returns the new node GUID, or empty on failure.
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString SpawnPropertyNode(UEdGraph* Graph, const FString& Kind, const FString& Ref, FVector2D Position, bool bDeclaration);
+
+    // Spawns a "Call Function" node for a function terminal graph (FunctionRef = terminal guid or name).
+    // Returns the new node GUID, or empty on failure.
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static FString SpawnCallFunctionNode(UEdGraph* Graph, const FString& FunctionRef, FVector2D Position);
+
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static bool NotifyGraphChanged(UEdGraph* Graph, bool bCompile);
+
+    UFUNCTION(BlueprintCallable, Category = "MCP|VoxelGraph")
+    static bool OpenVoxelGraphAsset(UObject* Asset);
+};