docs: remove references to deleted OpenClaw REST facade (port 8004)

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

docs/compat-removal-plan.md

@@ -61,7 +61,7 @@ backward-compatible behavior while migration settles.
 
 - OpenClaw currently appears through two different shapes:
   - WebSocket gateway integration on `:18789`
-  - optional REST surface at `backend.apps.openclaw_service` on `:8004`
+  
 - These are both valid, but they are not the same surface and should not be
   documented as interchangeable.
 

docs/current-architecture.md

@@ -83,7 +83,6 @@ Current service surfaces:
   - read-only explain/news APIs
 - `backend.apps.runtime_service` on `:8003`
   - runtime lifecycle and gateway process management
-- `backend.apps.openclaw_service` on `:8004`
   - optional OpenClaw REST facade
 - gateway WebSocket on `:8765`
   - live feed/event transport and pipeline coordination

docs/legacy-inventory.md

@@ -65,7 +65,7 @@ topology and service-routing policy are frozen.
 
 | Surface | Current State | Decision Needed |
 |---------|---------------|-----------------|
-| OpenClaw dual integration | REST facade (`:8004`) + Gateway WebSocket (`:18789`) | Which surface is the long-term contract? |
+| OpenClaw integration | Gateway WebSocket (port 18789) | Stable — REST facade removed |
 | Env-dependent service fallbacks | `TRADING_SERVICE_URL`, `NEWS_SERVICE_URL` fallbacks to local modules | Remove fallbacks and require explicit URLs? |
 | Split-service production deploy | Docs show gateway-first, dev uses split-service | Align production with dev topology? |
 
@@ -104,70 +104,6 @@ python3 -m backend.main \
 **Ownership**: ops-team
 **Status**: Stable and intentional
 
-### OpenClaw Dual Integration
-
-Two different integration surfaces exist for OpenClaw:
-
-#### A. REST Facade (Port 8004)
-
-**File**: `backend/apps/openclaw_service.py`
-**Routes**: `backend/api/openclaw.py` (prefix `/api/openclaw`)
-
-**Purpose**:
-- Read-only OpenClaw CLI integration
-- Typed Pydantic models for all responses
-- Direct HTTP/REST access to OpenClaw state
-
-**Use when**:
-- You need typed, stable API contracts
-- You want to poll OpenClaw status from external systems
-- You need programmatic access without WebSocket complexity
-
-**Example**:
-```bash
-curl http://localhost:8004/api/openclaw/status
-```
-
-#### B. Gateway WebSocket Integration (Port 18789)
-
-**Files**:
-- `backend/services/gateway_openclaw_handlers.py`
-- `shared/client/openclaw_websocket_client.py`
-
-**Purpose**:
-- Real-time bidirectional communication with OpenClaw
-- Event streaming and live updates
-- Integration with Gateway event flow
-
-**Use when**:
-- You need real-time updates
-- You're already connected to Gateway WebSocket
-- You want event-driven rather than polling architecture
-
-**Example**:
-```javascript
-// Frontend connects to ws://localhost:18789
-const ws = new WebSocket('ws://localhost:18789');
-```
-
-#### Key Differences
-
-| Aspect | REST Facade (8004) | Gateway WebSocket (18789) |
-|--------|-------------------|---------------------------|
-| Protocol | HTTP/REST | WebSocket |
-| Access pattern | Request/response | Event-driven |
-| Typing | Pydantic models | JSON messages |
-| Real-time | Polling required | Push notifications |
-| Use case | External integrations, scripts | Frontend, live dashboards |
-| Stability | Higher (explicit contracts) | Evolving with Gateway |
-
-**Decision needed**: Which surface becomes the long-term contract?
-- REST facade is more stable but read-only
-- WebSocket integration is more capable but tied to Gateway evolution
-
-**Ownership**: runtime-team
-**Status**: Deferred until topology final
-
 ### Dashboard Export Layer
 
 **Files**: `runs/<run_id>/team_dashboard/*.json`