Key features implemented:
- New i18n module with JSON-based message catalogs for multi-language support
- Added Russian (ru-RU) and English (en-US) localization files with 100+ messages
- PowerShell module ActivityWatch.Windows.I18n.psm1 with fallback mechanism
- Node.js validation and coverage analysis scripts for locale management
- Package.json configuration with semantic versioning and build tools
- README_RU.md documentation with integration examples and best practices
The implementation provides comprehensive internationalization support with automated validation, versioning, and fallback capabilities for robust multilingual deployments.