Flash 20,580 Landmark Seal (GW987)
Gemini 3.8 Flash sealed Grand Wave 987 at commit d39c28e, locking the 20,580 Landmark (jobs #20,561–#20,580). Fourth consecutive Landmark after Half-Thousand Apex 20,500 and the 20,520/20,540/20,560 chain.
Origin commit is daily_work_log-only; desk from commit message + chat trail. Path: GW988 toward the 20,600 Century Apex.