refactor: 系统优化 - 错误处理、输入验证、无限滚动

主要改进:
- 新增配置管理 (server/config.js)
- 新增日志工具 (server/utils/logger.js)
- 添加全局错误处理中间件，统一错误响应格式
- 添加输入验证和 AppError 错误类
- 重构 db.js 迁移逻辑，代码更清晰
- 前端列表改为无限滚动加载，每页 20 条
- 封装 AppState 状态管理模块

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/routes/records.js

@@ -1,18 +1,36 @@
 const express = require('express');
 const db = require('../db');
-const { getMonthRange } = require('../utils/helpers');
+const config = require('../config');
+const logger = require('../utils/logger');
+const { getMonthRange, AppError, validateRequired, validateNumber, validateInList } = require('../utils/helpers');
 
 const router = express.Router();
 
 // 新增记录
-router.post('/', (req, res) => {
-  const { type, category, amount, quantity, unit_price, rebate, boss, partner, source, destination, note, created_at } = req.body;
-  const stmt = db.prepare(`
-    INSERT INTO records (user_id, type, category, amount, quantity, unit_price, rebate, boss, partner, source, destination, note, created_at)
-    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
-  `);
-  const result = stmt.run(req.user.id, type, category, amount, quantity || null, unit_price || null, rebate || null, boss || null, partner || null, source || null, destination || null, note || null, created_at || new Date().toISOString());
-  res.json({ id: result.lastInsertRowid });
+router.post('/', (req, res, next) => {
+  try {
+    const { type, category, amount, quantity, unit_price, rebate, boss, partner, source, destination, note, created_at } = req.body;
+
+    // 输入验证
+    validateRequired(req.body, ['type', 'category', 'amount']);
+    validateInList(type, 'type', ['income', 'expense']);
+
+    const allCategories = [...config.categories.income, ...config.categories.expense];
+    validateInList(category, 'category', allCategories);
+
+    const validatedAmount = validateNumber(amount, '金额', 0);
+
+    const stmt = db.prepare(`
+      INSERT INTO records (user_id, type, category, amount, quantity, unit_price, rebate, boss, partner, source, destination, note, created_at)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+    `);
+    const result = stmt.run(req.user.id, type, category, validatedAmount, quantity || null, unit_price || null, rebate || null, boss || null, partner || null, source || null, destination || null, note || null, created_at || new Date().toISOString());
+
+    logger.info(`用户 ${req.user.username} 新增记录: ${category} ${validatedAmount}`);
+    res.json({ id: result.lastInsertRowid });
+  } catch (err) {
+    next(err);
+  }
 });
 
 // 通用分页查询函数
@@ -117,19 +135,45 @@ router.get('/', (req, res) => {
 });
 
 // 更新记录
-router.put('/:id', (req, res) => {
-  const { quantity, unit_price, rebate, amount, boss, partner, source, destination, note, created_at } = req.body;
-  db.prepare(`
-    UPDATE records SET quantity = ?, unit_price = ?, rebate = ?, amount = ?, boss = ?, partner = ?, source = ?, destination = ?, note = ?, created_at = ?
-    WHERE id = ? AND user_id = ?
-  `).run(quantity || null, unit_price || null, rebate || null, amount, boss || null, partner || null, source || null, destination || null, note || null, created_at || null, req.params.id, req.user.id);
-  res.json({ success: true });
+router.put('/:id', (req, res, next) => {
+  try {
+    const { quantity, unit_price, rebate, amount, boss, partner, source, destination, note, created_at } = req.body;
+    const id = Number(req.params.id);
+
+    if (!id || id <= 0) {
+      throw new AppError('无效的记录ID', 400);
+    }
+
+    const validatedAmount = validateNumber(amount, '金额', 0);
+
+    db.prepare(`
+      UPDATE records SET quantity = ?, unit_price = ?, rebate = ?, amount = ?, boss = ?, partner = ?, source = ?, destination = ?, note = ?, created_at = ?
+      WHERE id = ? AND user_id = ?
+    `).run(quantity || null, unit_price || null, rebate || null, validatedAmount, boss || null, partner || null, source || null, destination || null, note || null, created_at || null, id, req.user.id);
+
+    logger.debug(`用户 ${req.user.username} 更新记录: ${id}`);
+    res.json({ success: true });
+  } catch (err) {
+    next(err);
+  }
 });
 
 // 删除记录
-router.delete('/:id', (req, res) => {
-  db.prepare('DELETE FROM records WHERE id = ? AND user_id = ?').run(req.params.id, req.user.id);
-  res.json({ success: true });
+router.delete('/:id', (req, res, next) => {
+  try {
+    const id = Number(req.params.id);
+
+    if (!id || id <= 0) {
+      throw new AppError('无效的记录ID', 400);
+    }
+
+    db.prepare('DELETE FROM records WHERE id = ? AND user_id = ?').run(id, req.user.id);
+
+    logger.info(`用户 ${req.user.username} 删除记录: ${id}`);
+    res.json({ success: true });
+  } catch (err) {
+    next(err);
+  }
 });
 
 module.exports = router;