fix: agent_api 同步 dev（事务/_execute 遮蔽/600s 超时）

web/agent_api.py

@@ -142,11 +142,12 @@ def _agent_thread(run_id, prompt, cfg):
         agent.s.default_serial = cfg.get("default_serial") or agent.s.default_serial
         agent.on_step = on_step
 
-        async def _run():
+        async def _execute():
             await agent._load_tools()
             return await agent.run(prompt, cfg.get("default_serial") or "")
 
-        answer = asyncio.run(_run())
+        # 整体超时保护：模型/工具卡死时结束运行，避免单实例被永久占用
+        answer = asyncio.run(asyncio.wait_for(_execute(), timeout=600))
         with _lock:
             _run["state"] = "done"
             _run["answer"] = answer