refactor(docs): 简化README结构，更新技术栈和项目结构描述

backend/tests/test-database.js

@@ -0,0 +1,16 @@
+// 测试专用数据库配置
+const { Sequelize } = require('sequelize');
+
+// 创建测试用的SQLite内存数据库
+const testSequelize = new Sequelize('sqlite::memory:', {
+  logging: false, // 关闭SQL日志
+  dialect: 'sqlite',
+  storage: ':memory:',
+  define: {
+    timestamps: true,
+    underscored: false,
+    freezeTableName: false
+  }
+});
+
+module.exports = testSequelize;