HEL-269: 完成月结锁账、撤演示数据与代码收尾

锁账后写保护与闭期补录留痕；重开须审批并按版本链再结；列表/导出改走真实 API。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

tests/test_reminders.py

@@ -477,8 +477,8 @@ class MigrationTests(unittest.TestCase):
         versions = connection.execute(
             "SELECT version FROM schema_migrations ORDER BY version"
         ).fetchall()
-        self.assertEqual(9, versions[-1]["version"])
-        connection.execute("DELETE FROM schema_migrations WHERE version = 9")
+        self.assertEqual(10, versions[-1]["version"])
+        connection.execute("DELETE FROM schema_migrations WHERE version = 10")
         connection.executescript(
             """
             DROP TRIGGER IF EXISTS reminders_no_delete;