test: add pinned LES baseline and temporary candidate diagnostics

tests/validation/les/prepare.py

@@ -0,0 +1,63 @@
+"""Materialize pinned baseline/candidate headers under a new explicit output path."""
+
+import argparse
+import hashlib
+import json
+from pathlib import Path
+import shutil
+import subprocess
+
+HERE = Path(__file__).resolve().parent
+REPO = HERE.parents[2]
+DATA = HERE / "data"
+PIN = "d79e3f6f0a424f5bcc3a1a6d610313e49daf97a2"
+
+
+def manifest():
+    result = json.loads((DATA / "source_manifest.json").read_text())
+    if result["baseline_commit"] != PIN:
+        raise RuntimeError("Wrong baseline pin")
+    return result
+
+
+def verify_candidate(root):
+    for name, expected in manifest()["files"].items():
+        if hashlib.sha256((root / name).read_bytes()).hexdigest() != expected:
+            raise RuntimeError("Candidate header hash mismatch: " + name)
+
+
+def materialize(repo, output):
+    """Copy only the two exact source headers, then patch the isolated copy."""
+    expected = manifest()
+    headers = [
+        Path(name).relative_to("baseline")
+        for name in expected["files"]
+        if name.startswith("baseline/")
+    ]
+    for relative in headers:
+        wanted = expected["files"][str(Path("baseline") / relative)]
+        if hashlib.sha256((repo / relative).read_bytes()).hexdigest() != wanted:
+            raise RuntimeError("Production header does not match d79: " + str(relative))
+    output.mkdir(parents=True, exist_ok=False)
+    for mode in ("baseline", "patched"):
+        for relative in headers:
+            target = output / mode / relative
+            target.parent.mkdir(parents=True, exist_ok=True)
+            shutil.copyfile(repo / relative, target)
+    patch = DATA / "smagorinsky_normalization.patch"
+    subprocess.run(
+        ["git", "apply", "--check", str(patch)], cwd=output / "patched", check=True
+    )
+    subprocess.run(["git", "apply", str(patch)], cwd=output / "patched", check=True)
+    verify_candidate(output)
+    (output / "source_manifest.json").write_text(json.dumps(expected, indent=2) + "\n")
+    return output
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--repo", type=Path, default=REPO)
+    parser.add_argument("--output-dir", type=Path, required=True)
+    args = parser.parse_args()
+    materialize(args.repo.resolve(), args.output_dir.resolve())
+    print("Pinned baseline/candidate headers verified; production files unchanged.")