strengthen external parity diagnostics

tests/test_pyjhora_compare_cli.py

@@ -0,0 +1,17 @@
+import subprocess
+import sys
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+RUNNER = ROOT / "benchmarks" / "jyotish" / "scripts" / "run_pyjhora_compare.py"
+
+
+def test_pyjhora_compare_help_is_non_executing():
+    result = subprocess.run(
+        [sys.executable, str(RUNNER), "--help"], cwd=ROOT, capture_output=True, text=True, timeout=15
+    )
+
+    assert result.returncode == 0
+    assert "--build-local" in result.stdout
+    assert "FileNotFoundError" not in result.stderr