refactor(数据库): 优化模型关联初始化并移除外键检查

移除手动设置 FOREIGN_KEY_CHECKS 的冗余代码，改为在关联定义中直接设置 constraints: false
简化初始化流程，保持功能一致但代码更清晰

backend/models/ticketIndex.js

@@ -157,15 +157,20 @@ const initDefaultFaultCategories = async () => {
 };
 
 const initAssociations = () => {
-  Ticket.hasMany(TicketOperationRecord, { foreignKey: 'ticketId', as: 'operationRecords' });
-  TicketOperationRecord.belongsTo(Ticket, { foreignKey: 'ticketId' });
+  Ticket.hasMany(TicketOperationRecord, { 
+    foreignKey: 'ticketId', 
+    as: 'operationRecords',
+    constraints: false
+  });
+  TicketOperationRecord.belongsTo(Ticket, { 
+    foreignKey: 'ticketId',
+    constraints: false
+  });
 };
 
 const initializeModels = async () => {
   try {
-    await sequelize.query('SET FOREIGN_KEY_CHECKS = 0');
     await sequelize.sync({ alter: true });
-    await sequelize.query('SET FOREIGN_KEY_CHECKS = 1');
     console.log('工单相关数据表同步完成');
 
     initAssociations();
@@ -173,7 +178,6 @@ const initializeModels = async () => {
 
     console.log('工单系统数据初始化完成');
   } catch (error) {
-    await sequelize.query('SET FOREIGN_KEY_CHECKS = 1');
     console.error('初始化工单系统数据失败:', error);
   }
 };