kin: KIN-UI-002 Исправить падающие тесты миграции (регрессия KIN-ARCH-003) в core/db.py

agents/prompts/tester.md

@@ -39,6 +39,7 @@ For a specific test file: `python -m pytest tests/test_models.py -v`
 - One test per behavior — don't combine multiple assertions in one test without clear reason.
 - Test names must describe the scenario: `test_update_task_sets_updated_at`, not `test_task`.
 - Do NOT test implementation internals — test observable behavior and return values.
+- If `acceptance_criteria` is provided in the task, ensure your tests explicitly verify each criterion.
 
 ## Output format