- Add GET/PATCH /api/v1/settings endpoint for global config
- Add GlobalSettings component with editable sections: general (language,
quiet, attachment_send, idle_timeout), display (thinking/tool max len),
stream preview, rate limit, and log level
- Integrate global settings into System page with collapsible raw config
- Add "View All" link to Recent Sessions on Dashboard
- Add i18n translations for all global settings (en, zh, zh-TW, ja, es)
Made-with: Cursor