feat: 管理后台日志查询系统

后端：
- 新增 /api/logs 路由，支持日志文件列表、统计、查询
- 按日期/级别/关键词筛选日志

前端：
- 新增日志管理页面，展示今日统计和7天趋势
- 支持按级别筛选和关键词搜索
- 管理后台添加「系统日志」入口

server/src/routes/logs.ts

@@ -0,0 +1,145 @@
+import { Router } from 'express'
+import fs from 'fs'
+import path from 'path'
+import { requireAdmin } from '../middleware/requireAdmin'
+
+const router = Router()
+const LOG_DIR = path.resolve(process.env.LOG_DIR || './logs')
+
+/** 获取日志列表（最近7天） */
+router.get('/files', requireAdmin, (_req, res) => {
+  try {
+    if (!fs.existsSync(LOG_DIR)) {
+      return res.json({ code: 0, data: [] })
+    }
+
+    const files = fs.readdirSync(LOG_DIR)
+      .filter(f => f.endsWith('.log'))
+      .sort()
+      .reverse()
+      .slice(0, 7) // 最多返回7天
+
+    const fileList = files.map(f => {
+      const filePath = path.join(LOG_DIR, f)
+      const stat = fs.statSync(filePath)
+      return {
+        name: f,
+        date: f.replace('.log', ''),
+        size: stat.size,
+        modified: stat.mtime.toISOString()
+      }
+    })
+
+    res.json({ code: 0, data: fileList })
+  } catch (err) {
+    console.error('[Logs] List error:', err)
+    res.status(500).json({ code: 50000, message: '获取日志列表失败' })
+  }
+})
+
+/** 获取日志统计 */
+router.get('/stats', requireAdmin, (_req, res) => {
+  try {
+    if (!fs.existsSync(LOG_DIR)) {
+      return res.json({ code: 0, data: { today: { total: 0, errors: 0, slow: 0 }, files: [] } })
+    }
+
+    const today = new Date()
+    const dateStr = `${today.getFullYear()}-${String(today.getMonth() + 1).padStart(2, '0')}-${String(today.getDate()).padStart(2, '0')}`
+    const todayFile = path.join(LOG_DIR, `${dateStr}.log`)
+
+    let todayStats = { total: 0, errors: 0, slow: 0, warns: 0 }
+
+    if (fs.existsSync(todayFile)) {
+      const content = fs.readFileSync(todayFile, 'utf-8')
+      const lines = content.split('\n').filter(l => l.trim())
+      todayStats.total = lines.length
+      todayStats.errors = lines.filter(l => l.includes(' ERROR ')).length
+      todayStats.slow = lines.filter(l => l.includes('Slow request')).length
+      todayStats.warns = lines.filter(l => l.includes(' WARN ')).length
+    }
+
+    // 最近7天统计
+    const files = fs.readdirSync(LOG_DIR)
+      .filter(f => f.endsWith('.log'))
+      .sort()
+      .reverse()
+      .slice(0, 7)
+
+    const dailyStats = files.map(f => {
+      const filePath = path.join(LOG_DIR, f)
+      const content = fs.readFileSync(filePath, 'utf-8')
+      const lines = content.split('\n').filter(l => l.trim())
+      return {
+        date: f.replace('.log', ''),
+        total: lines.length,
+        errors: lines.filter(l => l.includes(' ERROR ')).length,
+        slow: lines.filter(l => l.includes('Slow request')).length
+      }
+    })
+
+    res.json({
+      code: 0,
+      data: {
+        today: todayStats,
+        daily: dailyStats
+      }
+    })
+  } catch (err) {
+    console.error('[Logs] Stats error:', err)
+    res.status(500).json({ code: 50000, message: '获取日志统计失败' })
+  }
+})
+
+/** 查询指定日期的日志 */
+router.get('/:date', requireAdmin, (req, res) => {
+  try {
+    const { date } = req.params
+    const { level, keyword, page = '1', pageSize = '100' } = req.query
+
+    // 日期格式校验
+    if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
+      return res.status(400).json({ code: 40001, message: '日期格式无效' })
+    }
+
+    const logFile = path.join(LOG_DIR, `${date}.log`)
+    if (!fs.existsSync(logFile)) {
+      return res.json({ code: 0, data: { lines: [], total: 0 } })
+    }
+
+    const content = fs.readFileSync(logFile, 'utf-8')
+    let lines = content.split('\n').filter(l => l.trim())
+
+    // 按级别过滤
+    if (level && level !== 'all') {
+      lines = lines.filter(l => l.includes(` ${level.toUpperCase()} `))
+    }
+
+    // 按关键词过滤
+    if (keyword && typeof keyword === 'string') {
+      const kw = keyword.toLowerCase()
+      lines = lines.filter(l => l.toLowerCase().includes(kw))
+    }
+
+    const total = lines.length
+    const pNum = Math.max(1, parseInt(page as string) || 1)
+    const pSize = Math.min(500, Math.max(1, parseInt(pageSize as string) || 100))
+    const offset = (pNum - 1) * pSize
+    const paged = lines.slice(offset, offset + pSize)
+
+    res.json({
+      code: 0,
+      data: {
+        lines: paged,
+        total,
+        page: pNum,
+        pageSize: pSize
+      }
+    })
+  } catch (err) {
+    console.error('[Logs] Query error:', err)
+    res.status(500).json({ code: 50000, message: '查询日志失败' })
+  }
+})
+
+export default router