docs: restructure workflow subflows and promote deployment architecture map to root tier

docs: add deployment reference and deploy scripts ...

- Add docs/deployment_reference.md with complete proxy architecture
- Add .agent/workflows/deploy_to_production.md and envoy_control_plane.md
- Add remote_deploy.sh for 1-click CI/CD
- Fix Nginx websocket Upgrade maps and connection closures
- Update ai-hub Dockerfile to handle proxy headers
- Update local_deployment.sh and docker-compose.yml