Запрос на слияние 'first_branch' (#1) из first_branch в master

update demo/README.md

create demo/README.md

create dev/solution.py

update spec/codex.md

update demo/README.md

create demo/README.md

create spec/program.cs

update codex.md

update SYSTEM_PROMPT.md

create SYSTEM_PROMPT.md

delete SYSTEM_PROMPT.md

create SYSTEM_PROMPT.md

update assignment.py

update test.py