feat: OpenClaw WebSocket integration with workspace file preview

- Migrate OpenClaw from HTTP (port 8004) to WebSocket (port 18789)
- Add workspace file list and content preview handlers
- Add OpenClawStatus component with agent/skills view
- Add OpenClawView panel in trader interface
- Add Zustand store for OpenClaw state management
- Fix gateway logging noise (yfinance, websockets)
- Fix RunWorkspaceManager.get_agent_asset_dir attribute error
- Handle missing workspace files gracefully in preview

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/apps/openclaw_service.py

@@ -0,0 +1,49 @@
+# -*- coding: utf-8 -*-
+"""Read-only OpenClaw CLI FastAPI surface."""
+
+from __future__ import annotations
+
+from fastapi import Depends, FastAPI
+
+from backend.api import openclaw_router
+from backend.apps.cors import add_cors_middleware
+from backend.api.openclaw import get_openclaw_cli_service
+
+
+def create_app() -> FastAPI:
+    """Create the OpenClaw service app."""
+    app = FastAPI(
+        title="EvoTraders OpenClaw Service",
+        description="Read-only OpenClaw CLI integration service surface",
+        version="0.1.0",
+    )
+
+    add_cors_middleware(app)
+
+    @app.get("/health")
+    async def health_check(
+        service=Depends(get_openclaw_cli_service),
+    ) -> dict[str, object]:
+        return service.health()
+
+    @app.get("/api/status")
+    async def api_status(
+        service=Depends(get_openclaw_cli_service),
+    ) -> dict[str, object]:
+        return {
+            "status": "operational",
+            "service": "openclaw-service",
+            "openclaw": service.health(),
+        }
+
+    app.include_router(openclaw_router)
+    return app
+
+
+app = create_app()
+
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run(app, host="0.0.0.0", port=8004)