看板任务完成通知机制

def build_task_notification_message(task, runtime_summary) -> str:
    """构造 <system-notification> 消息。"""
    summary = runtime_summary.get("runtime_description", "")
    err_msg = runtime_summary.get("runtime_err_msg", "")
    pr_url  = runtime_summary.get("runtime_pr_url", "")
    status_label = "失败" if err_msg else "待审核"

    parts = [
        f"看板任务「{task.title}」(#{task.id}) 已完成执行，"
        f"状态已更新为「{status_label}」。",
    ]
    if summary:
        parts.append(f"结果摘要：{summary}")
    if pr_url:
        parts.append(f"PR 链接：{pr_url}")
    if err_msg:
        parts.append(f"错误信息：{err_msg}")
    parts.append("请根据结果进行后续处理。")
    body = "\n".join(parts)
    return f"<system-notification>\n{body}\n</system-notification>"


async def notify_origin_session(
    task: AgentBoardTask,
    exclude_session_id: str | None,
) -> None:
    """无头任务完成后，向来源会话注入通知。异步调度，不阻塞 finally。"""
    # 点对点通知：优先使用 origin_session_id
    target_sid = task.origin_session_id
    if not target_sid or target_sid == exclude_session_id:
        # 回退：从项目会话中找 conversation 类型
        target_sid = _find_fallback_conversation_session(
            task.project_id, exclude_session_id
        )
    if not target_sid:
        return

    engine = get_engine()
    session = engine.session_manager.index.get(target_sid)
    if session is None:
        return

    runtime_summary = task_runtime_summary(task)
    message = build_task_notification_message(task, runtime_summary)

    # 会话正在对话中 → 追加待处理消息
    if engine._has_running_chat(target_sid):
        append_pending_user_message(target_sid, message)
        return

    # 会话空闲 → 启动新对话轮次
    sio = get_socketio_server()
    bridge = create_socket_bridge(sio, engine, target_sid)
    try:
        await engine.chat(target_sid, message, event_handler=bridge)
    except RuntimeError as exc:
        if "already running" in str(exc):
            # TOCTOU 竞态：判断时空闲，调用时已有 chat → 降级为消息注入
            append_pending_user_message(target_sid, message)
        else:
            logger.exception("notify origin session %s failed", target_sid)
    except Exception:
        logger.exception("notify origin session %s failed", target_sid)

async def _run_auto_task() -> None:
    try:
        await engine.chat(...)
    except Exception:
        ...
    finally:
        get_background_sessions().pop(session_id, None)
        store = get_agent_board_store()
        updated_task = store.get_task(task.id, project_id)
        if updated_task is not None:
            sync_task_runtime_events(updated_task)
            _settle_session_from_submit_result(updated_task)
            if updated_task.status == AgentBoardTaskStatus.RUNNING:
                updated_task = store.update_task(
                    updated_task.id, project_id,
                    status=AgentBoardTaskStatus.REVIEW,
                )
            if updated_task is not None:
                await emit_board_task_changed(project_id, updated_task, "updated")
                # ── 新增：异步通知前台会话（fire-and-forget）──
                asyncio.create_task(
                    notify_origin_session(updated_task, exclude_session_id=session_id),
                    name=f"board-notify:{updated_task.id}",
                )

// kanban create 命令中，自动读取 BLADE_SESSION_ID
originSessionID := os.Getenv("BLADE_SESSION_ID")
body := map[string]interface{}{
    "title":       title,
    "description": description,
    "assignee_type": assigneeType,
    "assignee_name": assigneeName,
}
if originSessionID != "" {
    body["origin_session_id"] = originSessionID
}