Add pre-commit configuration for code quality checks

[johnny603]

Summary

Describe the changes introduced by this pull request.

Type of Change

Select all that apply:

• feat: New feature
• fix: Bug fix
• docs: Documentation changes
• test: New or updated tests
• refactor: Code restructuring without behavior changes
• chore: Maintenance, tooling, CI/CD, dependencies
• ci: GitHub Actions or automation changes

Related Issue

Closes #

Testing

Describe how you tested your changes.

pytest
ruff check .
bandit -r .

Checklist

• My commit messages follow the Conventional Commits specification.
• I have added or updated tests where appropriate.
• I have updated documentation where appropriate.
• All CI checks pass.
• My changes do not introduce known security issues.

Example Commit Messages

feat: add Docker-based puzzle validation
fix: correct level submission response handling
docs: update installation instructions
test: add health endpoint smoke tests
refactor: simplify puzzle lookup logic
chore: upgrade Flask dependency
ci: add CodeQL workflow

Screenshots / Logs (Optional)

Attach screenshots or logs if relevant.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.