chore: happy 出口通初始提交（前端 React + 后端 Express，采购管理已原生化）

backend/db/db.js

@@ -0,0 +1,64 @@
+const Database = require('better-sqlite3-multiple-ciphers');
+const fs = require('fs');
+const path = require('path');
+
+const DATA_DIR = process.env.DATA_DIR || path.join(__dirname, '../data');
+const DB_PATH = path.join(DATA_DIR, 'trade.db');
+
+// 确保数据目录存在
+if (!fs.existsSync(DATA_DIR)) {
+  fs.mkdirSync(DATA_DIR, { recursive: true });
+}
+
+// 创建数据库连接
+const db = new Database(DB_PATH);
+
+// 启用外键约束
+db.pragma('foreign_keys = ON');
+
+// 性能优化
+db.pragma('journal_mode = WAL');
+db.pragma('synchronous = NORMAL');
+
+// 初始化数据库结构
+function initDatabase() {
+  const schema = fs.readFileSync(path.join(__dirname, 'schema.sql'), 'utf-8');
+  db.exec(schema);
+  console.log('✓ 数据库初始化完成');
+}
+
+// 检查数据库是否已初始化
+const tableExists = db.prepare(
+  "SELECT name FROM sqlite_master WHERE type='table' AND name='users'"
+).get();
+
+if (!tableExists) {
+  initDatabase();
+}
+
+// 创建默认管理员账号（如果不存在）
+function createDefaultAdmin() {
+  const crypto = require('crypto');
+  const adminExists = db.prepare('SELECT id FROM users WHERE username = ?').get('admin');
+
+  if (!adminExists) {
+    // 生成默认密码哈希：admin123
+    const salt = crypto.randomBytes(16).toString('hex');
+    const hash = crypto.scryptSync('admin123', salt, 64).toString('hex');
+    const passwordHash = `scrypt$${salt}$${hash}`;
+
+    db.prepare(`
+      INSERT INTO users (username, password_hash, display_name, role, created_at)
+      VALUES (?, ?, ?, ?, ?)
+    `).run('admin', passwordHash, '管理员', 'admin', new Date().toISOString());
+
+    console.log('✓ 默认管理员账号已创建');
+    console.log('  用户名: admin');
+    console.log('  密码: admin123');
+    console.log('  请登录后立即修改密码！');
+  }
+}
+
+createDefaultAdmin();
+
+module.exports = db;