fix(backend): reject malformed timestamp (#12554)

packages/backend/src/misc/id/aidx.ts

@@ -41,3 +41,7 @@ export function parseAidx(id: string): { date: Date; } {
 	const time = parseInt(id.slice(0, TIME_LENGTH), 36) + TIME2000;
 	return { date: new Date(time) };
 }
+
+export function isSafeAidxT(t: number): boolean {
+	return t > TIME2000;
+}