feat(tools): refactor migrate OpenClaw from custom tool to builtin tool

Create OpenClawTool class inheriting BuiltinTool with dedicated config
Remove all x-openclaw special handling from CustomTool (~270 lines)
Add multi-operation support (print_task, device_query, image_understand, general)
Change ensure_builtin_tools_initialized to incremental mode for auto-provisioning
Fix OperationTool and LangchainAdapter to support OpenClaw operation routing

api/app/core/tools/configs/builtin/openclaw_tool.json

@@ -0,0 +1,15 @@
+{
+  "name": "openclaw_tool",
+  "description": "调用OpenClaw Agent远程服务",
+  "tool_class": "OpenClawTool",
+  "category": "agent",
+  "requires_config": true,
+  "version": "1.0.0",
+  "enabled": true,
+  "parameters": {
+    "server_url": "",
+    "api_key": "",
+    "agent_id": "main"
+  },
+  "tags": ["agent", "openclaw", "multimodal", "3d-printing", "builtin"]
+}

api/app/core/tools/configs/builtin_tools.json

@@ -30,5 +30,18 @@
     "parameters": {
       "api_key": {"type": "string", "description": "百度搜索API密钥", "sensitive": true, "required": true}
     }
+  },
+  "openclaw": {
+    "name": "OpenClaw远程Agent",
+    "description": "OpenClaw Agent远程服务",
+    "tool_class": "OpenClawTool",
+    "category": "agent",
+    "requires_config": true,
+    "version": "1.0.0",
+    "enabled": true,
+    "parameters": {
+      "server_url": {"type": "string", "description": "OpenClaw Gateway 地址", "required": true},
+      "api_key": {"type": "string", "description": "OpenClaw API Key", "sensitive": true, "required": true}
+    }
   }
 }