check_contributors.py --stub writes a placeholder commit count #1271

Where: scripts/check_contributors.py (stub_entry).

Current gap: A new entry's commit count is set to its PR count until --fix --commits runs, so the file is briefly wrong and the sort order uses a made-up tie-breaker.

Suggested approach: Let --stub LOGIN --commits take the commit count from the same data --commits reads, and print a reminder when it is run without it.

Done when: --stub LOGIN --commits leaves a file that --commits passes, covered by a test with saved data.