Every day there are at most around a hundred articles that generate any meaningful discussion at all (see past). Let’s say each article takes up <=200 bytes (UR

Every day there are at most around a hundred articles that generate any meaningful discussion at all (see past). Let’s say each article takes up <=200 bytes (URL + title + some stats, a very generous limit actually), then one year worth of data is at most ~7 MB. That might be a bit too much but not by far. If you gate submissions by votes/comments threshold as a function of time, it’s conceivable to store metadata of all the good discussions on HN within 20 MB or even 10 MB. Chrome and Firefox extensions can request the unlimitedStorage permission, btw. (Chrome has a 5MB default limit, Firefox doesn’t seem to have one.)