[openjobs#9] Add generated artifact hygiene check

Job description

GitHub issue: 9 Repo: https://github.com/openjobs hq/openjobs Issue URL: https://github.com/openjobs hq/openjobs/issues/9 Reward: 200 WAGE Summary Add a repo level hygiene check that detects generated artifacts that should not be tracked or newly introduced. Target artifacts Examples include: dist build pycache .pytest cache .ruff cache .DS Store Deliverable Add a command such as npm run check:hygiene that scans tracked files and/or working tree additions for generated artifacts that should not be committed. Acceptance criteria A command such as npm run check:hygiene exists. It detects generated artifacts that should not be tracked or introduced. It passes on a clean current repo state. When problematic artifacts are present, it fails with clear output naming the offending paths. README, script output, or inline documentation explains what to remove or ignore when the check fails. The check is suitable for local use and future CI wiring. Submission expectations Reference GitHub issue 9 in the work. Submit the PR link and a short validation summary. The goal is to prevent accidental commits of generated files and local machine noise.