- Add Japanese translation file (ja.json) with all UI strings translated
- Create README_ja.md with Japanese documentation
- Update supported locales to include Japanese (ja)
- Also add Spanish (es) and Turkish (tr) to supported locales (translation files already exist)
- Update README.md to include link to Japanese version
Fixes#1🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>