tools: visual-review screenshot pipeline

- AGigLineShotActor (dev-only): walks a fixed camera list in -game mode,
  captures via FScreenshotRequest, quits. Test content only.
- ue_build_review_map.py builds /Game/Test/ReviewMap from current content
  (gray floor, key light, sky, MPFB character, 1 m scale cubes).
- render_screenshots.sh: build map -> run game -> collect PNGs into
  gitignored Screenshots/.
- Screenshots/README.md (committed) describes each capture with approval
  state; AGENTS.md gains the visual-review instructions.

Game/GigLine/Source/GigLine/GigLineShotActor.cpp

@@ -0,0 +1,78 @@
+#include "GigLineShotActor.h"
+
+#include "Camera/CameraActor.h"
+#include "Engine/World.h"
+#include "GameFramework/PlayerController.h"
+#include "UnrealClient.h"
+
+AGigLineShotActor::AGigLineShotActor()
+{
+	PrimaryActorTick.bCanEverTick = true;
+	PrimaryActorTick.bStartWithTickEnabled = true;
+}
+
+void AGigLineShotActor::BeginPlay()
+{
+	Super::BeginPlay();
+	NextShot();
+}
+
+void AGigLineShotActor::Tick(float DeltaSeconds)
+{
+	Super::Tick(DeltaSeconds);
+
+	if (bWaitingForSettle)
+	{
+		SettleCountdown -= DeltaSeconds;
+		if (SettleCountdown <= 0.f)
+		{
+			bWaitingForSettle = false;
+			const FString FileName = FString::Printf(TEXT("review-%02d-%s"), CurrentShot,
+				CurrentShot < ShotNames.Num() ? *ShotNames[CurrentShot] : *FString::FromInt(CurrentShot));
+			// Resolution is the game window's; the runner passes -ResX/-ResY.
+			FScreenshotRequest::RequestScreenshot(FileName, false, false);
+			bWaitingForScreenshot = true;
+		}
+		return;
+	}
+
+	if (bWaitingForScreenshot && !FScreenshotRequest::IsScreenshotRequested())
+	{
+		bWaitingForScreenshot = false;
+		UE_LOG(LogTemp, Log, TEXT("GigLineShotActor: captured %s"), *FScreenshotRequest::GetFilename());
+		++CurrentShot;
+		NextShot();
+	}
+}
+
+void AGigLineShotActor::NextShot()
+{
+	if (!PlayerController)
+	{
+		PlayerController = GetWorld()->GetFirstPlayerController();
+	}
+
+	if (CurrentShot >= ShotLocations.Num() || !PlayerController)
+	{
+		UE_LOG(LogTemp, Log, TEXT("GigLineShotActor: done (%d shots)"), CurrentShot);
+		if (bQuitWhenDone)
+		{
+			PlayerController->ConsoleCommand(TEXT("quit"));
+		}
+		return;
+	}
+
+	if (CurrentCamera)
+	{
+		CurrentCamera->Destroy();
+	}
+
+	FActorSpawnParameters Params;
+	Params.ObjectFlags |= RF_Transient;
+	CurrentCamera = GetWorld()->SpawnActor<ACameraActor>(
+		ACameraActor::StaticClass(), ShotLocations[CurrentShot], ShotRotations[CurrentShot], Params);
+	PlayerController->SetViewTarget(CurrentCamera);
+
+	SettleCountdown = SettleSeconds;
+	bWaitingForSettle = true;
+}