Split native Periscope (periscope/src) from inherited PinScope (periscope/dependency).

Keep validate.py and the finding engine as-is. AGPL LICENSE stays at the repo root.
Docker overlays dependency then src. Do not delete the inherited tree.

scripts/materialize-frontend.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# Overlay PinScope frontend (dependency) with native Periscope files (src).
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+DEST="${1:-"$ROOT/.merge/frontend"}"
+python3 - "$ROOT" "$DEST" <<'PY'
+import shutil
+import sys
+from pathlib import Path
+
+root, dest = Path(sys.argv[1]), Path(sys.argv[2])
+dep = root / "periscope" / "dependency" / "frontend"
+src = root / "periscope" / "src" / "frontend"
+if dest.exists():
+    shutil.rmtree(dest)
+shutil.copytree(dep, dest, dirs_exist_ok=True)
+if src.is_dir():
+    shutil.copytree(src, dest, dirs_exist_ok=True)
+print(dest)
+PY