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/tests/test_openclaw_cli_service.py

@@ -0,0 +1,60 @@
+# -*- coding: utf-8 -*-
+"""Tests for the OpenClaw CLI service wrapper."""
+
+from pathlib import Path
+
+import pytest
+
+from backend.services.openclaw_cli import OpenClawCliError, OpenClawCliService
+
+
+class _Completed:
+    def __init__(self, *, returncode=0, stdout="", stderr=""):
+        self.returncode = returncode
+        self.stdout = stdout
+        self.stderr = stderr
+
+
+def test_openclaw_cli_service_runs_json_command(monkeypatch, tmp_path):
+    captured = {}
+
+    def _fake_run(command, **kwargs):
+        captured["command"] = command
+        captured["cwd"] = kwargs["cwd"]
+        return _Completed(stdout='{"sessions":[{"key":"main/session-1"}]}')
+
+    monkeypatch.setattr("backend.services.openclaw_cli.subprocess.run", _fake_run)
+
+    service = OpenClawCliService(base_command=["openclaw"], cwd=tmp_path, timeout_seconds=3)
+    payload = service.list_sessions()
+
+    assert payload["sessions"][0]["key"] == "main/session-1"
+    assert captured["command"] == ["openclaw", "sessions", "--json"]
+    assert captured["cwd"] == tmp_path
+
+
+def test_openclaw_cli_service_raises_on_failure(monkeypatch, tmp_path):
+    def _fake_run(command, **kwargs):
+        return _Completed(returncode=7, stdout="", stderr="boom")
+
+    monkeypatch.setattr("backend.services.openclaw_cli.subprocess.run", _fake_run)
+
+    service = OpenClawCliService(base_command=["openclaw"], cwd=tmp_path, timeout_seconds=3)
+
+    with pytest.raises(OpenClawCliError) as exc_info:
+        service.list_cron_jobs()
+
+    assert exc_info.value.exit_code == 7
+    assert exc_info.value.stderr == "boom"
+
+
+def test_openclaw_cli_service_can_extract_single_session(monkeypatch, tmp_path):
+    def _fake_run(command, **kwargs):
+        return _Completed(stdout='{"sessions":[{"key":"main/session-1","agentId":"main"}]}')
+
+    monkeypatch.setattr("backend.services.openclaw_cli.subprocess.run", _fake_run)
+
+    service = OpenClawCliService(base_command=["openclaw"], cwd=tmp_path, timeout_seconds=3)
+    session = service.get_session("main/session-1")
+
+    assert session["agentId"] == "main"