[matthewp]

Changes

• Fixes persona review requests being silently dropped after a push. On Deduplicate CSS for components used both statically and with client:only on the same page astro#18176 the author persona pushed and requested astro-reviewer 3 seconds later; GitHub's review_requested payload still named the previous head, so review setup saw a different live head, returned stale, and exited. The reviewer never ran and the request stayed pending with nothing to retry it.
• Persona-triggered reviews (review request or assignment) now review the pull request's live head instead of rejecting a mismatch. The request applies to the pull request, not a commit. Label-triggered reviews keep the existing stale check.
• The author workflow waits (up to ~10s) for GitHub to report the pushed commit as the head before requesting reviews again, which removes the race at the source for Factory's own author. It proceeds either way.
• The review workflow now logs a warning when a review doesn't start (ignored/stale with the reason), and an info line when it reviews a head newer than the trigger's.

Testing

• tests/review-persona.test.ts: a persona review whose trigger names an older head is ready and reviews the live head (base SHA unchanged).
• tests/persona-handoff.test.ts: waitForPullHead returns once the head matches (case-insensitive) and gives up without throwing after its attempt budget.
• The existing label-trigger test still asserts a moved head is stale.

Docs

• No docs update needed: this restores the documented persona review loop.