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/main.py

@@ -29,6 +29,7 @@ from backend.runtime.manager import (
     set_global_runtime_manager,
     clear_global_runtime_manager,
 )
+from backend.gateway_server import configure_gateway_logging
 from backend.services.gateway import Gateway
 from backend.services.market import MarketService
 from backend.services.storage import StorageService
@@ -38,6 +39,7 @@ load_dotenv()
 logger = logging.getLogger(__name__)
 loguru.logger.disable("flowllm")
 loguru.logger.disable("reme_ai")
+configure_gateway_logging(verbose=os.getenv("LOG_LEVEL", "").upper() == "DEBUG")
 _prompt_loader = get_prompt_loader()