ForgeProvider.diff now takes the head commit it must describe. The GitHub
provider reads headRefOid before and after `gh pr diff` and returns the new
ForgeFailure code `stale` when either read names another commit, so the
forge panel never caches a patch under a head it does not describe. A stale
read polls the change request at once, and the changes view waits for the
next status before reading again.
Status polling pages reviewThreads up to the new `maxReviewThreads` setting
(default 1,000) instead of counting only the first 100, and sets
ChangeRequestSnapshot.threadsTruncated when the count is a lower bound.
Yichen Jiang
94336c6b3d