refactor: reorganize type definitions and improve type safety
build: add lodash and @types/lodash as dependencies
chore: update tsconfig and vite config for path aliases
style: improve code organization and add documentation comments
fix: correct type usage in LanguageSwitcher component
perf: implement snackbar provider for global notifications
test: add new test interfaces and utility functions
ci: update pnpm-lock.yaml with new dependencies
- Add i18next and related dependencies for internationalization
- Implement language switcher component with English and Chinese support
- Create translation files for English and Chinese locales
- Update login and home pages to use translations
- Configure i18n initialization with language detection
- Add dayjs locale synchronization with i18n language changes
- Update tsconfig and eslint to ignore new locales directory
- Remove unused App.css and simplify index.css
- Update npmrc with mirror configuration
