Fill zh-CN, zh-TW, fr, and es catalogs for the migrated keys. zh-CN and zh-TW
are independently localized (Simplified vs Traditional script + Taiwan
vocabulary, e.g. 项目/任务 vs 專案/工作), not script-converted. Translations are
machine-drafted and flagged for human review in locales/TRANSLATION_STATUS.md.
Add docs/i18n-contributing.md (translate / add-a-language / --lang usage) and
cross-link it from contributing.md and cli-reference.md. i18n:status reports
100% for all four locales across the migrated key set.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
