test(validation): enforce catalog and checklist parity

Implement catalog source comparison and exact eval checklist parity with deterministic validation coverage.

scripts/test_validate_case_checklist.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+import importlib.util
+import json
+import tempfile
+import unittest
+from pathlib import Path
+
+SPEC = importlib.util.spec_from_file_location(
+    "validator", Path(__file__).parent / "validate-case-checklist.py"
+)
+assert SPEC is not None and SPEC.loader is not None
+validator = importlib.util.module_from_spec(SPEC)
+SPEC.loader.exec_module(validator)
+
+
+class ChecklistValidatorTest(unittest.TestCase):
+    def test_current_checklist_matches_manifests(self) -> None:
+        self.assertEqual(validator.validate(), [])
+
+    def test_missing_orphan_and_duplicate_rows_fail(self) -> None:
+        source = json.loads(validator.CHECKLIST.read_text())
+        source["rows"] = source["rows"][:-1]
+        source["rows"].append({"skill": "not-a-skill", "case_id": "orphan"})
+        source["rows"].append(source["rows"][0])
+        with tempfile.TemporaryDirectory() as directory:
+            path = Path(directory) / "checklist.json"
+            path.write_text(json.dumps(source))
+            errors = validator.validate(path)
+        self.assertTrue(any("missing checklist rows" in error for error in errors))
+        self.assertTrue(any("orphan checklist rows" in error for error in errors))
+        self.assertTrue(any("duplicate checklist rows" in error for error in errors))
+
+
+if __name__ == "__main__":
+    unittest.main()