Change history now supports infinite scroll and previewing prior versions

The change history viewer just got a meaningful UX upgrade.

• Infinite scroll pagination — the timeline now loads eight entries at a time as you scroll, instead of a single bulk fetch that slowed down on prolific articles.
• View details — you can now preview any prior version of an article in a read-only state, so you can see exactly what the article looked like at a point in time without restoring it.
• Read-only editor — the preview uses a disabled state of the actual editor, so the formatting, embeds, and structure match what readers would have seen.

Other quality-of-life changes shipped in the same release: cleaner loading states across the update workflow, better validation in the publish form, and refined category and tag pickers.

If you actively edit and revise articles, the new history viewer makes it much easier to retrace your steps.