Add English and Japanese localization

[keishingu]

Thanks for building such a great app! I’d love to help make HogLite accessible to more users.

Summary

• add device-locale detection with expo-localization and translations with i18n-js
• keep English as the source language and fallback, and add Japanese translations
• localize navigation, onboarding, insights, activity, exceptions, settings, dialogs, errors, date ranges, numbers, and durations
• declare English and Japanese in the iOS bundle configuration
• keep event names, property keys, project/dashboard names, URLs, and API-provided content unchanged

The locale resolver maps ja and regional variants such as ja-JP to Japanese. Unsupported locales fall back to English. Translation keys are typed from the English locale so missing Japanese keys fail type checking.

expo-localization is pinned to 16.1.0, the lowest stable release that compiles with the current Xcode Swift SDK.

Verification

• npx jest --runInBand --no-watchman
• npx expo config --type public
• Japanese UI checked on a physical iPhone using a local development build
• unsupported locale fallback and localized date, number, and duration formatting covered by tests