vocabulary ref and schema guard test

tests/test_storage_migrations.py

@@ -37,6 +37,69 @@ def test_initialize_is_idempotent_and_applies_expected_columns(tmp_path):
     assert "content_chunks" in tables
 
 
+def test_approved_registry_schema_allows_future_nullable_vocabulary_ref(tmp_path):
+    database_path = tmp_path / "registry.sqlite3"
+    store = RegistryStore(database_path)
+    store.initialize()
+
+    approved_tables = {
+        "approved_abilities",
+        "approved_capabilities",
+        "approved_features",
+    }
+
+    with sqlite3.connect(database_path) as connection:
+        table_sql = {
+            table: connection.execute(
+                "SELECT sql FROM sqlite_master WHERE type = 'table' AND name = ?",
+                (table,),
+            ).fetchone()[0]
+            for table in approved_tables
+        }
+        indexes = {
+            table: [
+                {
+                    "name": row[1],
+                    "unique": bool(row[2]),
+                    "columns": [
+                        column[2]
+                        for column in connection.execute(
+                            f"PRAGMA index_info({row[1]!r})"
+                        )
+                    ],
+                }
+                for row in connection.execute(f"PRAGMA index_list({table})")
+            ]
+            for table in approved_tables
+        }
+        foreign_keys = {
+            table: [
+                {
+                    "from": row[3],
+                    "to_table": row[2],
+                    "to_column": row[4],
+                }
+                for row in connection.execute(f"PRAGMA foreign_key_list({table})")
+            ]
+            for table in approved_tables | {"review_decisions"}
+        }
+        review_columns = {
+            row[1] for row in connection.execute("PRAGMA table_info(review_decisions)")
+        }
+
+    assert all("CHECK" not in sql.upper() for sql in table_sql.values())
+    for table_indexes in indexes.values():
+        assert all(
+            not (index["unique"] and index["columns"] == ["name"])
+            for index in table_indexes
+        )
+    for table_foreign_keys in foreign_keys.values():
+        assert all(key["to_column"] != "name" for key in table_foreign_keys)
+        assert all(key["from"] != "name" for key in table_foreign_keys)
+    assert {"repository_id", "analysis_run_id", "action", "notes"} <= review_columns
+    assert not {"ability_name", "capability_name", "feature_name"} & review_columns
+
+
 def test_delete_repository_cascades_registry_and_review_rows(tmp_path):
     service = make_service(tmp_path)
     repository = service.register_repository(