refactor(模型关系): 重构模型关联关系定义位置，从模型文件移至路由文件

backend/models/NetworkCard.js

@@ -1,6 +1,5 @@
 const { DataTypes } = require('sequelize');
 const { sequelize } = require('../db');
-const Device = require('./Device');
 
 const NetworkCard = sequelize.define('NetworkCard', {
   nicId: {
@@ -63,7 +62,4 @@ const NetworkCard = sequelize.define('NetworkCard', {
   ]
 });
 
-NetworkCard.belongsTo(Device, { foreignKey: 'deviceId', as: 'device' });
-Device.hasMany(NetworkCard, { foreignKey: 'deviceId', as: 'networkCards' });
-
 module.exports = NetworkCard;