🧹 Clean up legacy build files and move to archive

- Remove old GitBook configuration files (_config.yml, book.json)
- Remove legacy deployment scripts (deploy-*.sh)
- Files preserved in archive/ directory for reference
- Streamline repository structure for React-based deployment

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: beihaili