feat: unify recovery, updates, and schedules under Maintenance

src/lib/server/maintenance/settings.ts

@@ -0,0 +1,9 @@
+import { db } from '../db/index.js';
+export function readSetting<T>(key: string, fallback: T): T {
+    const row = db().prepare('SELECT value FROM settings WHERE key = ?').get(key) as { value: string } | undefined;
+    return row ? JSON.parse(row.value) : fallback;
+}
+export function writeSetting(key: string, value: unknown): void {
+    db().prepare('INSERT INTO settings (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value = excluded.value')
+        .run(key, JSON.stringify(value));
+}