Update-progress phases were a pure time guess, so a fast update sat on "fetch"
then snapped all four green at once. Now the host updater publishes its real
macro-stage and the page tracks it:
- update.sh / install.sh write the current stage (fetch|build|restart|migrate|
done) to run/update-phase.json — best-effort (|| true, never aborts an update).
- new public GET /update-status.json serves that stage (whitelisted) to the page.
- update-progress.blade.php drives the checklist from the feed in REAL order
(fetch → build → restart → migrate), falling back to the time heuristic when no
feed is present, and completes on the feed's 'done' (or the version flip, with a
25s grace fail-safe). Like the 502 fix, the live experience lands one update
after this ships (the page shown DURING an update is the old version's).
Also: Versions changelog series + page are now #[Url]-synced (?series=&page=),
so a series/page is shareable and survives reload / back-button.
Tests: /update-status.json (null / whitelisted / rejected stage), the page polls
the feed, and the changelog deep-link reads ?series=&page=.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>