Initial commit: Vertical Partition Streaming plugin (UE 5.7)

Bounded vertical route partition / streaming for handcrafted spiral climb maps
(Only Up / Only Climb). Not World Partition, not Level Instances as core arch.

- Z-cell segmentation + optional XY subcells, editor builder + commandlet
- NonDestructive visibility backend + streaming-level backend
- Offline HLOD proxies: MergedMesh / SimplifiedProxy (ProxyLOD)
- Universal Level Instance + Packed Level Actor + HISM support (flatten+merge)
- Vertical-aware runtime streamer (full/preload/HLOD/unload, hysteresis,
  velocity prediction, fall-risk), WP-style debug viz + vp.* console
- Safe-by-default: only static decor streams; sky/lights/gameplay stay persistent

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

Source/VerticalPartitionEditor/VerticalPartitionEditor.Build.cs

@@ -0,0 +1,37 @@
+// Copyright IHY. Vertical Partition Streaming plugin (editor module).
+using UnrealBuildTool;
+
+public class VerticalPartitionEditor : ModuleRules
+{
+	public VerticalPartitionEditor(ReadOnlyTargetRules Target) : base(Target)
+	{
+		PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
+
+		PublicDependencyModuleNames.AddRange(new string[]
+		{
+			"Core",
+			"CoreUObject",
+			"Engine",
+			"VerticalPartition",
+		});
+
+		PrivateDependencyModuleNames.AddRange(new string[]
+		{
+			"UnrealEd",
+			"Slate",
+			"SlateCore",
+			"InputCore",
+			"EditorSubsystem",
+			"ToolMenus",
+			"Projects",
+			"AssetRegistry",
+			"AssetTools",
+			"MeshMergeUtilities",
+			"MeshDescription",
+			"StaticMeshDescription",
+			"MaterialUtilities",
+			"MeshReductionInterface",
+			"LevelEditor",
+		});
+	}
+}