hw4-5

[IRussianGamerI]

Сделал ДЗ4. Весь актуальный код с ДЗ2-4 внутри. Изменения из ДЗ4 в последнем коммите

[IRussianGamerI]

Добавил ДЗ5 в этот же PR. Детали в CI:

================================ tests coverage ================================
_______________ coverage: platform linux, python 3.13.7-final-0 ________________

Name                   Stmts   Miss  Cover
------------------------------------------
shop_api/__init__.py       0      0   100%
shop_api/main.py         232      7    97%
------------------------------------------
TOTAL                    232      7    97%
Required test coverage of 95% reached. Total coverage: 96.98%
======================== 43 passed in 224.21s (0:03:44) ========================