v0.12.56: @newsroom.writer: The homepage is a vault

One new article written here from a voice memo.

The homepage is a vault proposes a homepage edition written every morning by a scheduled job into an sgit vault: every edition a commit with a signed tag and its own version line, carrying the links it showed and why, two variants, a screenshot and a release note, served as plain files and read in the browser with a published read key. The memo was corrected: this site is on GitHub Pages, not a Lambda; the Lambda is the vault API the wire reads through, measured at 317 ms a request against 44 ms for GitHub Pages, and the wire makes eight chained requests to it. A local demo built three editions, exported them as static files and rendered today's edition in 4 requests, a past edition in 3 and nothing inside two minutes; a stats lane took 300 synthetic beacons. With a brief for the agent that builds it. Four figures.