Update all documentation to reflect removal of OpenClaw REST service:
- README.md, README_zh.md: remove service table entry
- deploy/README.md: update port range 8000-8003
- services/README.md: remove 8004 references and service list
- docs/compat-removal-plan.md: remove REST surface mention
- docs/current-architecture.md: remove service reference
- docs/legacy-inventory.md: simplify to WebSocket-only description
Follow-up to: refactor(openclaw): remove REST facade