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.

Tools/render_screenshots.sh

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+# Render in-game screenshots for visual review into <repo>/Screenshots/ (gitignored).
+#
+# Usage: Tools/render_screenshots.sh
+# Rebuilds /Game/Test/ReviewMap from current content, runs the game on it
+# (the GigLineShotActor walks three cameras, captures, quits), then copies
+# the PNGs into Screenshots/.
+set -euo pipefail
+
+REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+ENGINE="${UE_ENGINE_DIR:-/run/media/system/DATA/Engines/UE_5.8.4}"
+PROJ="$REPO/Game/GigLine/GigLine.uproject"
+
+echo "== 1/3 build review map =="
+cd "$ENGINE"
+./Engine/Binaries/Linux/UnrealEditor-Cmd "$PROJ" \
+  -run=pythonscript -script="$REPO/Tools/ue_build_review_map.py" \
+  -nullrhi -unattended -nopause -stdout
+cat /tmp/ue-review-map-result.txt
+
+echo "== 2/3 run game on review map =="
+./Engine/Binaries/Linux/UnrealEditor-Cmd "$PROJ" /Game/Test/ReviewMap \
+  -game -ResX=1920 -ResY=1080 -nopause -nosplash -stdout
+
+echo "== 3/3 collect screenshots =="
+mkdir -p "$REPO/Screenshots"
+rm -f "$REPO"/Screenshots/review-*.png
+found=0
+for src in \
+  "$REPO/Game/GigLine/Saved/Screenshots"/*/review-*.png \
+  "$REPO/Game/GigLine/Saved/Screenshots"/*/*/review-*.png \
+  "$HOME/.config/Epic/GigLine/Saved/Screenshots"/*/review-*.png; do
+  [ -e "$src" ] || continue
+  cp -f "$src" "$REPO/Screenshots/"
+  found=1
+done
+[ "$found" = "1" ] || { echo "ERROR: no review-*.png found"; exit 1; }
+ls -la "$REPO/Screenshots"