feat: 小菜记账 v1.0 - 完整功能实现

核心功能：
- 记账CRUD（支出/收入/分类/备注/日期）
- 统计分析（概览/分类占比/每日趋势）
- 预算管理（按月设置/进度条/超支提醒）
- 数据导出CSV

安全与认证：
- HMAC-SHA256签名token认证
- 用户数据隔离
- 输入验证与错误处理
- CORS配置

前端优化：
- 骨架屏加载
- 账单按日期分组
- 预算页面重构（快捷预设+Numpad）
- SvgIcon组件（H5+微信双端适配）
- 下拉刷新

后端优化：
- 共享日期工具函数
- 数据库连接池优化
- 健康检查端点
- 优雅关闭处理

技术栈：
- 前端：Uni-app (Vue 3 + Pinia)
- 后端：Node.js + Express + MySQL

server/src/db/connection.ts

@@ -0,0 +1,17 @@
+import mysql from 'mysql2/promise'
+
+const pool = mysql.createPool({
+  host: process.env.DB_HOST || 'localhost',
+  user: process.env.DB_USER || 'xiaocai',
+  password: process.env.DB_PASSWORD || 'xiaocai123',
+  database: process.env.DB_NAME || 'xiaocai',
+  waitForConnections: true,
+  connectionLimit: 10,
+  queueLimit: 0,
+})
+
+;(pool as any).on('error', (err: any) => {
+  console.error('[DB] Pool error:', err?.message || err)
+})
+
+export default pool

server/src/db/init.ts

@@ -0,0 +1,51 @@
+import mysql from 'mysql2/promise'
+import pool from './connection'
+import { readFileSync } from 'fs'
+import { join } from 'path'
+
+export async function initDatabase() {
+  const dbName = process.env.DB_NAME || 'xiaocai'
+
+  // 先用不指定数据库的连接，确保数据库存在
+  const bootstrap = await mysql.createConnection({
+    host: process.env.DB_HOST || 'localhost',
+    user: process.env.DB_USER || 'xiaocai',
+    password: process.env.DB_PASSWORD || 'xiaocai123',
+    multipleStatements: true,
+  })
+
+  await bootstrap.query(`CREATE DATABASE IF NOT EXISTS \`${dbName}\` DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci`)
+  await bootstrap.end()
+
+  // 用独立连接执行建表和填充（需要 multipleStatements）
+  const initConn = await mysql.createConnection({
+    host: process.env.DB_HOST || 'localhost',
+    user: process.env.DB_USER || 'xiaocai',
+    password: process.env.DB_PASSWORD || 'xiaocai123',
+    database: dbName,
+    multipleStatements: true,
+  })
+  try {
+    const schemaPath = join(__dirname, 'schema.sql')
+    const seedPath = join(__dirname, 'seed.sql')
+
+    const schema = readFileSync(schemaPath, 'utf-8')
+    const cleanSchema = schema
+      .replace(/CREATE DATABASE.*?;/gi, '')
+      .replace(/USE\s+\w+;/gi, '')
+    await initConn.query(cleanSchema)
+
+    const seed = readFileSync(seedPath, 'utf-8')
+    await initConn.query(seed)
+
+    console.log('[DB] Database initialized')
+  } catch (err: any) {
+    if (err.code === 'ER_DUP_ENTRY' || err.errno === 1062) {
+      console.log('[DB] Already initialized, skipping seed')
+    } else {
+      console.error('[DB] Init failed:', err.message)
+    }
+  } finally {
+    await initConn.end()
+  }
+}

server/src/db/schema.sql

@@ -0,0 +1,48 @@
+CREATE TABLE IF NOT EXISTS users (
+  id INT AUTO_INCREMENT PRIMARY KEY,
+  openid VARCHAR(100) UNIQUE,
+  session_key VARCHAR(100),
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+CREATE TABLE IF NOT EXISTS categories (
+  id INT AUTO_INCREMENT PRIMARY KEY,
+  user_id INT DEFAULT 0 COMMENT '0=默认分类, 其他=用户自定义',
+  name VARCHAR(50) NOT NULL,
+  icon VARCHAR(50) NOT NULL,
+  color VARCHAR(20) NOT NULL,
+  type ENUM('expense', 'income') NOT NULL,
+  sort_order INT DEFAULT 0,
+  is_custom TINYINT(1) DEFAULT 0,
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  UNIQUE KEY uk_user_name_type (user_id, name, type),
+  INDEX idx_user_custom (user_id, is_custom)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+CREATE TABLE IF NOT EXISTS transactions (
+  id INT AUTO_INCREMENT PRIMARY KEY,
+  user_id INT NOT NULL,
+  amount INT NOT NULL COMMENT '单位：分',
+  type ENUM('expense', 'income') NOT NULL,
+  category_id INT,
+  note VARCHAR(200),
+  date DATE NOT NULL,
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  INDEX idx_user_date (user_id, date),
+  INDEX idx_user_type_date (user_id, type, date),
+  FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
+  FOREIGN KEY (category_id) REFERENCES categories(id) ON DELETE SET NULL
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+CREATE TABLE IF NOT EXISTS budgets (
+  id INT AUTO_INCREMENT PRIMARY KEY,
+  user_id INT NOT NULL,
+  amount INT NOT NULL COMMENT '单位：分',
+  month VARCHAR(7) NOT NULL COMMENT '格式：2026-05',
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  UNIQUE KEY uk_user_month (user_id, month),
+  FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

server/src/db/seed.sql

@@ -0,0 +1,17 @@
+INSERT IGNORE INTO categories (user_id, name, icon, color, type, sort_order) VALUES
+(0, '餐饮', 'Coffee', '#FF8C69', 'expense', 1),
+(0, '饮品', 'Coffee', '#FF8C69', 'expense', 2),
+(0, '购物', 'ShoppingBag', '#FFB347', 'expense', 3),
+(0, '交通', 'Car', '#6C9BCF', 'expense', 4),
+(0, '住房', 'Home', '#7BC67E', 'expense', 5),
+(0, '医疗', 'Heart', '#FF6B6B', 'expense', 6),
+(0, '教育', 'BookOpen', '#6C9BCF', 'expense', 7),
+(0, '娱乐', 'Film', '#B39DDB', 'expense', 8),
+(0, '服饰', 'Shirt', '#FFD166', 'expense', 9),
+(0, '美容', 'Smile', '#FF8C69', 'expense', 10),
+(0, '通讯', 'Smartphone', '#6C9BCF', 'expense', 11),
+(0, '其他', 'MoreHorizontal', '#BFB3B3', 'expense', 12),
+(0, '工资', 'DollarSign', '#7BC67E', 'income', 1),
+(0, '副业', 'TrendingUp', '#7BC67E', 'income', 2),
+(0, '理财', 'PieChart', '#7BC67E', 'income', 3),
+(0, '其他收入', 'Plus', '#BFB3B3', 'income', 4);