With the merge gate in place, a Gaia DR3 outage no longer ships a HYG-only catalogue: the ETL skips the unreachable source, and validateMerge then fails on the survivor count. That is the right outcome and the wrong message: "68 000 HYG stars found no Gaia counterpart" sends the reader looking at the merge. Gaia contributing nothing is now checked first, by name. Two comments said Gaia was best-effort, in data-refresh.yml and on the merge in fetchStars. They now say what happens instead. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016jxMkwA2rbicdGxHosecYi