Automatische DB-Backups: nächtlich, gzip, Rotation, optional Discord-Upload

- SQLite-Online-Backup (WAL-sicher) täglich 03:00 → data/backups/*.db.gz, 14 Tage Rotation
- Optional Offsite-Kopie als Upload in einen privaten Discord-Kanal (Setting)
- Setup-Seite: Toggle, Upload-Kanal, 'Backup jetzt'-Button; letztes Backup im Status-Panel

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/index.js

@@ -3,6 +3,7 @@ import { startBot } from './bot/client.js';
 import { startWebServer } from './web/server.js';
 import { scheduleWeeklyRecap } from './bot/weekly-recap.js';
 import { startWatchdog } from './bot/watchdog.js';
+import { scheduleBackups } from './backup.js';
 
 process.on('unhandledRejection', (error) => {
     console.error('[main] Unhandled Rejection:', error);
@@ -13,6 +14,7 @@ try {
     await startWebServer(client);
     scheduleWeeklyRecap(client);
     startWatchdog(client);
+    scheduleBackups(client);
 } catch (error) {
     console.error('[main] Start fehlgeschlagen:', error);
     process.exit(1);