chore(repo): retire duplicate nested source mirror

scripts/verify_repository_layout.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+"""Fail when a second GeoIntel source tree reappears below the repository root."""
+
+from __future__ import annotations
+
+import argparse
+from pathlib import Path
+
+
+CANONICAL_MARKERS = (
+    "backend/app/main.py",
+    "frontend/package.json",
+    "docs/API_CONTRACTS.md",
+)
+
+
+def nested_mirror_markers(repo_root: Path) -> list[str]:
+    nested = repo_root / "geointel"
+    return [marker for marker in CANONICAL_MARKERS if (nested / marker).is_file()]
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        "--repo-root",
+        type=Path,
+        default=Path(__file__).resolve().parents[1],
+    )
+    args = parser.parse_args()
+    repo_root = args.repo_root.resolve()
+    missing = [marker for marker in CANONICAL_MARKERS if not (repo_root / marker).is_file()]
+    if missing:
+        raise SystemExit(f"Canonical GeoIntel repository markers are missing: {missing}")
+    duplicates = nested_mirror_markers(repo_root)
+    if duplicates:
+        raise SystemExit(
+            "Nested GeoIntel repository mirror detected below geointel/: "
+            f"{duplicates}. The repository root is the only canonical source tree."
+        )
+    print("Repository layout verified: one canonical GeoIntel source tree")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())