test(storage): pin the identity-bearing sort key

tests/test_bootstrap.py

@@ -1,7 +1,7 @@
 import unittest
 from unittest.mock import Mock
 
-from app.common.bootstrap import identifier, verify_table
+from app.common.bootstrap import SORT_KEY, identifier, verify_table
 
 
 class TestBootstrap(unittest.TestCase):
@@ -11,9 +11,18 @@ class TestBootstrap(unittest.TestCase):
             with self.subTest(value=value), self.assertRaises(ValueError):
                 identifier(value)
 
-    def test_old_sorting_key_fails_without_mutating_data(self):
+    def test_sorting_key_includes_deterministic_record_identity(self):
+        self.assertEqual(
+            SORT_KEY,
+            "service_type, radio_access_type, cell_id, session_start_time, msisdn, cdr_id",
+        )
+
+    def test_sorting_key_without_record_identity_fails_without_mutating_data(self):
         client = Mock()
-        client.query.return_value.result_rows = [("ReplacingMergeTree", "service_type, radio_access_type, cell_id, session_start_time, msisdn")]
+        client.query.return_value.result_rows = [(
+            "ReplacingMergeTree",
+            "service_type, radio_access_type, cell_id, session_start_time, msisdn",
+        )]
         with self.assertRaisesRegex(RuntimeError, "reset"):
             verify_table(client, "telecom", "cdr_records")
         client.command.assert_not_called()