Учебный код проверен локально при подготовке статьи, не в Искре и не в GitHub CI.
Python 3.13.2; команда: python3 -m unittest -v

ИСХОДНЫЙ ВАРИАНТ
test_after_end_is_excluded (test_orders.DateIntervalTests.test_after_end_is_excluded) ... ok
test_before_start_is_excluded (test_orders.DateIntervalTests.test_before_start_is_excluded) ... ok
test_cancelled_order_is_excluded (test_orders.DateIntervalTests.test_cancelled_order_is_excluded) ... ok
test_last_day_is_included (test_orders.DateIntervalTests.test_last_day_is_included) ... FAIL
test_one_day_interval (test_orders.DateIntervalTests.test_one_day_interval) ... FAIL

======================================================================
FAIL: test_last_day_is_included (test_orders.DateIntervalTests.test_last_day_is_included)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/koshatinko/.codex/worktrees/profession-draft-guides/iskra-marketing/creatives/cases/ispravit-bag-i-otkryt-pr/example-input/test_orders.py", line 14, in test_last_day_is_included
    self.assertEqual(self.ids("2026-10-30", "2026-10-31"), ["A1", "A2", "A3"])
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Lists differ: ['A1'] != ['A1', 'A2', 'A3']

Second list contains 2 additional elements.
First extra element 1:
'A2'

- ['A1']
+ ['A1', 'A2', 'A3']

======================================================================
FAIL: test_one_day_interval (test_orders.DateIntervalTests.test_one_day_interval)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/koshatinko/.codex/worktrees/profession-draft-guides/iskra-marketing/creatives/cases/ispravit-bag-i-otkryt-pr/example-input/test_orders.py", line 17, in test_one_day_interval
    self.assertEqual(self.ids("2026-10-31", "2026-10-31"), ["A2", "A3"])
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Lists differ: [] != ['A2', 'A3']

Second list contains 2 additional elements.
First extra element 0:
'A2'

- []
+ ['A2', 'A3']

----------------------------------------------------------------------
Ran 5 tests in 0.001s

FAILED (failures=2)

ИСПРАВЛЕННЫЙ ЭТАЛОН
test_after_end_is_excluded (test_orders.DateIntervalTests.test_after_end_is_excluded) ... ok
test_before_start_is_excluded (test_orders.DateIntervalTests.test_before_start_is_excluded) ... ok
test_cancelled_order_is_excluded (test_orders.DateIntervalTests.test_cancelled_order_is_excluded) ... ok
test_last_day_is_included (test_orders.DateIntervalTests.test_last_day_is_included) ... ok
test_one_day_interval (test_orders.DateIntervalTests.test_one_day_interval) ... ok

----------------------------------------------------------------------
Ran 5 tests in 0.000s

OK