The behind-count (banner._check_via_local_git) measures HEAD..origin/main, but
_recent_upstream_commits logged HEAD..@{upstream}. On a feature-branch checkout
@{upstream} is the branch's own tip (0 commits), so the changelog came back
empty while behind>0 — the overlay then showed generic filler instead of what
changed. Pin the commit range to origin/main so count and changelog agree.
Verified against a checkout 11 behind origin/main: now returns 11 commits.
87ac7cac13