fix(server): suppress mongoose reserved-key warning on Check.errors

Mongoose 8 logs a reserved-key warning at boot because the Check schema
defines an `errors` field, which collides with Mongoose's internal
document `errors` accessor. The field is intentional and safe to keep,
so opt out of the warning via `suppressReservedKeysWarning: true`.

Closes #1539

server/src/db/models/Check.ts

@@ -271,6 +271,7 @@ const CheckSchema = new Schema<CheckDocument>(
 	{
 		timestamps: true,
 		strict: false,
+		suppressReservedKeysWarning: true,
 		timeseries: {
 			timeField: "createdAt",
 			metaField: "metadata",