Default-branch counting covered Tangled only, so a GitHub commit on a side branch still counted. Now every source is marked and counted_refs reads `on_default = 1` for all of them: - The GitHub crawler marks each commit by the branch that first returned it; the default branch is read first. A side-branch commit merged later keeps its old committer date, which the incremental `since` window would miss, so the default branch is read in full while the repository has any side-branch-only references. - scripts/github_activity.py sends `on_default` per commit. The inbox stores report rows with the report's mark replacing the stored one, so a newer report can say a commit is only on a side branch. Reports without the field count every commit, as they did. - The migration marks existing GitHub references as on the default branch, so they keep counting until a newer scan or a `--full` report marks them. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Change-Id: Ic8f94bad4a9d02f58b9740aef1e7f5cb3c8af977