* feat: optimize email filtering with frontend-only search
- Remove backend keyword parameter from mail APIs (breaking change)
- Implement frontend filtering on current page (20-100 items)
- Add message_id database index for UPDATE performance
- Support desktop and mobile responsive layouts
- Update API documentation and CHANGELOG
BREAKING CHANGE: /admin/mails and /user_api/mails no longer accept keyword parameter
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* fix: restore Mail ID query input in Index.vue
- Keep showMailIdQuery UI input for querying specific mail by ID
- Triggered when URL contains mail_id parameter
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
