diff --git a/scripts/run_tests_batched.py.legacy b/scripts/run_tests_batched.py.legacy
new file mode 100644
index 00000000..c08ebd2b
--- /dev/null
+++ b/scripts/run_tests_batched.py.legacy
@@ -0,0 +1,109 @@
+"""Run the test suite in alphabetical batches of 32 files.
+
+Behavior:
+  - Per-batch subprocess timeout of 180s. Exceeding the timeout counts
+    as a batch failure (the watchdog in tests/conftest.py bounds the
+    actual pytest hang at 30s, but the outer timeout is the
+    runner-level safety net).
+  - Per-batch elapsed time reported in the header line.
+  - pytest's own exit-code based failure detection (subprocess
+    CalledProcessError) is preserved for batches that finish but
+    contain test failures.
+  - Final summary lists all files in any failed batch (per file, not
+    per batch, so the user can re-run individual files).
+
+Usage:
+  uv run python scripts/run_tests_batched.py
+  uv run python scripts/run_tests_batched.py --batch-size 16
+  uv run python scripts/run_tests_batched.py --timeout 300
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import subprocess
+import sys
+import time
+
+
+def run_tests(batch_size: int, timeout: int) -> int:
+ test_dir: str = "tests"
+ if not os.path.isdir(test_dir):
+  print(f"ERROR: '{test_dir}' directory not found", file=sys.stderr)
+  return 2
+ test_files: list[str] = sorted(
+  f for f in os.listdir(test_dir)
+  if f.startswith("test_") and f.endswith(".py")
+ )
+ if not test_files:
+  print(f"ERROR: no test files found in '{test_dir}'", file=sys.stderr)
+  return 2
+ batches: list[list[str]] = [
+  test_files[i : i + batch_size] for i in range(0, len(test_files), batch_size)
+ ]
+ failed_files: list[str] = []
+ batch_timings: list[float] = []
+
+ print(f"Starting test execution of {len(test_files)} files in {len(batches)} batches of {batch_size} (timeout {timeout}s per batch)...")
+ print()
+
+ for batch_idx, batch in enumerate(batches, start=1):
+  cmd: list[str] = ["uv", "run", "pytest", "--maxfail=10"] + [
+   os.path.join(test_dir, f) for f in batch
+  ]
+  print(f"Batch {batch_idx}/{len(batches)} ({len(batch)} files):")
+  start: float = time.perf_counter()
+  try:
+   subprocess.run(cmd, check=True, timeout=timeout)
+  except subprocess.TimeoutExpired:
+   elapsed: float = time.perf_counter() - start
+   batch_timings.append(elapsed)
+   print(f"  >>> Batch {batch_idx} TIMED OUT after {elapsed:.1f}s (limit {timeout}s)")
+   failed_files.extend(batch)
+  except subprocess.CalledProcessError as e:
+   elapsed = time.perf_counter() - start
+   batch_timings.append(elapsed)
+   print(f"  >>> Batch {batch_idx} FAILED after {elapsed:.1f}s (pytest exit {e.returncode})")
+   failed_files.extend(batch)
+  else:
+   elapsed = time.perf_counter() - start
+   batch_timings.append(elapsed)
+   print(f"  >>> Batch {batch_idx} passed in {elapsed:.1f}s")
+  print()
+
+ print("=" * 70)
+ if failed_files:
+  failed_batch_count: int = sum(
+   1 for batch in batches if any(f in failed_files for f in batch)
+  )
+  print(f"Total batches: {len(batches)}; failed batches: {failed_batch_count}")
+  print(f"Failed files: {len(failed_files)}")
+  print("=" * 70)
+  for f in failed_files:
+   print(f" - {f}")
+  print("=" * 70)
+  return 1
+ total_time: float = sum(batch_timings)
+ avg: float = total_time / max(len(batch_timings), 1)
+ print(f"All {len(batches)} batches passed in {total_time:.1f}s (avg {avg:.1f}s per batch)")
+ print("=" * 70)
+ return 0
+
+
+def main() -> None:
+ ap: argparse.ArgumentParser = argparse.ArgumentParser(description=__doc__.split("\n\n")[0])
+ ap.add_argument("--batch-size", type=int, default=32, help="tests per batch (default: 32)")
+ ap.add_argument("--timeout", type=int, default=180, help="seconds per batch (default: 180)")
+ args: argparse.Namespace = ap.parse_args()
+ if args.batch_size <= 0:
+  print("ERROR: --batch-size must be positive", file=sys.stderr)
+  sys.exit(2)
+ if args.timeout <= 0:
+  print("ERROR: --timeout must be positive", file=sys.stderr)
+  sys.exit(2)
+ sys.exit(run_tests(args.batch_size, args.timeout))
+
+
+if __name__ == "__main__":
+ main()