Add the optional Forward+ desktop HQ build

Package a Forward+ preset with volumetric fog, SDFGI and a volumetric flashlight
for a separate Linux/Windows Desktop HQ zip. Gate the effects on a real
RenderingDevice, tune LATE fog, and adapt local light falloff for Godot 4.7.
Record the Compatibility/Forward+ A/B captures and metrics, add the artifact to
the build/publish scripts, and keep the default Compatibility/Web path
unchanged. Headless 231/231, Python 87/87; exported HQ binary boots with Vulkan.

tools/build_releases.sh

@@ -11,6 +11,7 @@
 #   build/gig-line-windows-<version>.exe
 #   build/gig-line-macos-<version>.zip
 #   build/gig-line-web-<version>.zip  (Godot web build: static hosting, no threads)
+#   build/gig-line-desktop-hq-<version>.zip  (optional Forward+ Linux/Windows)
 #
 set -euo pipefail
 
@@ -49,6 +50,30 @@ with zipfile.ZipFile(out, "w", zipfile.ZIP_DEFLATED) as archive:
 PYZIP
 fi
 
+echo "==> Packaging optional Desktop HQ build (Forward+)"
+HQ_DIR="build/desktop-hq"
+rm -rf "$HQ_DIR"
+mkdir -p "$HQ_DIR"
+cp "build/gig-line-linux-${VERSION}.x86_64" "$HQ_DIR/"
+cp "build/gig-line-windows-${VERSION}.exe" "$HQ_DIR/"
+cp packaging/desktop_hq/override.cfg "$HQ_DIR/"
+cp packaging/desktop_hq/README.txt "$HQ_DIR/"
+rm -f "build/gig-line-desktop-hq-${VERSION}.zip"
+if command -v zip >/dev/null 2>&1; then
+  (cd "$HQ_DIR" && zip -q -r "../gig-line-desktop-hq-${VERSION}.zip" .)
+else
+  python3 - "$PWD/$HQ_DIR" "$PWD/build/gig-line-desktop-hq-${VERSION}.zip" <<'PYZIP'
+import os, sys, zipfile
+src, out = sys.argv[1], sys.argv[2]
+with zipfile.ZipFile(out, "w", zipfile.ZIP_DEFLATED) as archive:
+    for root, _dirs, files in os.walk(src):
+        for name in files:
+            path = os.path.join(root, name)
+            archive.write(path, os.path.relpath(path, src))
+PYZIP
+fi
+rm -rf "$HQ_DIR"
+
 echo ""
 echo "Artifacts:"
 ls -la build/*"${VERSION}"*

tools/publish_release.sh

@@ -67,6 +67,7 @@ extras=(
   "build/gig-line-setup-$VERSION.exe"
   "build/gig-line-$VERSION-x86_64.AppImage"
   "build/gig-line-web-$VERSION.zip"
+  "build/gig-line-desktop-hq-$VERSION.zip"
 )
 all_artifacts=("${portables[@]}")
 for f in "${extras[@]}"; do