feat: automated backup and production monitoring

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

server/src/engine/backup.ts

@@ -0,0 +1,53 @@
+import { copyFileSync, readdirSync, unlinkSync, mkdirSync, existsSync } from 'fs'
+import { join, dirname } from 'path'
+import { fileURLToPath } from 'url'
+import { logger } from '../lib/logger.js'
+
+const __dirname = dirname(fileURLToPath(import.meta.url))
+const DB_PATH = process.env.DB_PATH || join(__dirname, '..', '..', 'data', 'botfights.db')
+const BACKUP_DIR = join(dirname(DB_PATH), 'backups')
+const MAX_BACKUPS = 7
+
+/** Create a timestamped backup of the database */
+export function createBackup(): string {
+  mkdirSync(BACKUP_DIR, { recursive: true })
+
+  const timestamp = new Date().toISOString().slice(0, 10)
+  const backupPath = join(BACKUP_DIR, `botfights-${timestamp}.db`)
+
+  copyFileSync(DB_PATH, backupPath)
+  logger.info('backup', `created backup: ${backupPath}`)
+
+  // Rotate: keep only the latest MAX_BACKUPS
+  rotateBackups()
+
+  return backupPath
+}
+
+/** Remove old backups beyond MAX_BACKUPS */
+function rotateBackups(): void {
+  if (!existsSync(BACKUP_DIR)) return
+
+  const files = readdirSync(BACKUP_DIR)
+    .filter(f => f.startsWith('botfights-') && f.endsWith('.db'))
+    .sort()
+    .reverse()
+
+  for (let i = MAX_BACKUPS; i < files.length; i++) {
+    const path = join(BACKUP_DIR, files[i])
+    try {
+      unlinkSync(path)
+      logger.info('backup', `rotated out: ${files[i]}`)
+    } catch { /* ok */ }
+  }
+}
+
+/** Start daily backup timer */
+export function startDailyBackups(): void {
+  // Run first backup after 1 minute, then every 24 hours
+  setTimeout(() => {
+    createBackup()
+    setInterval(() => createBackup(), 24 * 60 * 60 * 1000)
+  }, 60_000)
+  logger.info('backup', 'daily backups scheduled')
+}