v0.60.0

A page nobody has reviewed yet now says so. It used to show nothing at all where its freshness belongs, so a reader could not tell "fresh" from "forgotten". The new state is called "Not reviewed" and is deliberately neutral in colour: a page nobody has looked at is not overdue, and every page starts here. Its dot is an outlined circle, so the four states stay distinguishable without colour.

The hook documentation and the code agree again. Seven filters the plugin fires were documented nowhere: the two access-denied filters, the anonymous feedback ceiling, the two archive limits, the import time budget and the export user identifier. All seven are written up. Three hooks that were announced as planned and never built are gone. A test now fails if either side drifts from the other.

CHANGELOG.md moves to the Keep a Changelog format, with dates and headings instead of the readme syntax it had borrowed, and the smoke test checks that both changelogs carry an entry for the released version.

Nothing needs doing on update.