Fresh download, install and version counters for up to 100 listings.

The catalog stores the values seen at the last real change of a listing; counters and package versions change over time. These values may be cached for up to 15 minutes; gerado_em gives their reference date. Listings without a record are simply absent. GET /api/listings/:id already applies these values on top of the record. Returns: { itens, gerado_em, ttl_s }