When current_tag == latest_tag, _check_repo_release returned behind=0
and reported 'Up to date' even if master had moved hundreds of commits
past the tag. This was visible as Agent: v2026.5.16-593-gedb2d9105
alongside a green 'Up to date' pill in Settings.
Run 'git describe --tags --always' after computing behind==0. If the
output includes a -N-gSHA suffix the tag is not at HEAD; return None so
_check_repo_branch runs and counts the real commit gap via rev-list.
When HEAD is exactly on the latest tag the new branch is never taken and
behaviour is unchanged.
Fixes#2653.
Abdul Munim
d04805b0d7