chore: remove legacy configuration files

[nanasess]

Deleted the following configuration files:

• .scrutinizer.yml
• .styleci.yml
• .travis.yml
• phpcs.xml.dist

[claude]

Pull Request Review

This PR removes legacy configuration files that are no longer needed. Here's my analysis:

✅ Positive Aspects

1. Good housekeeping: Removing unused legacy configuration files reduces repository clutter and maintenance overhead.

2. Modern CI/CD in place: The repository already has a robust GitHub Actions workflow (.github/workflows/ci.yml) that replaces the functionality of the removed files:

   • Travis CI → GitHub Actions CI/CD
   • Scrutinizer CI → PHPStan for static analysis
   • StyleCI → PHP-CS-Fixer for code formatting
   • phpcs.xml.dist → PHP-CS-Fixer configuration

🔧 Recommended Follow-up Actions

1. Update .gitattributes: Remove references to the deleted files:

   • /.scrutinizer.yml export-ignore
   • /.styleci.yml export-ignore
   • /.travis.yml export-ignore
   • /phpcs.xml.dist export-ignore

2. Update CLAUDE.md: The project documentation still references PSR-2 and phpcs:

   • Line 27: vendor/bin/phpcs src tests
   • Line 60: PSR-2コーディング標準に準拠

   Consider updating these to reflect the current PHP-CS-Fixer usage.

3. Update composer.json scripts: The check-style and fix-style scripts still reference phpcs/phpcbf, but PHP-CS-Fixer is now the primary tool.

🎯 Assessment Summary

• Code Quality: ✅ Clean removal, no code logic affected
• Potential Bugs: ✅ None - these are configuration files only
• Performance: ✅ N/A - configuration files don't impact runtime performance
• Security: ✅ No security implications
• Test Coverage: ✅ N/A - no test changes needed

📝 Overall Recommendation

APPROVE with suggested follow-up cleanup. This is a straightforward maintenance task that improves repository hygiene. The modern CI/CD pipeline already provides superior functionality to the removed legacy tools.