CORRECTION: DSG Keystone Practice Not Deployed as Feature

AIVN corrects article s19w35719: GPT-5.5 confirms commit 7adb9ed is an ops-only receipt recording Worker action evidence under src=keystone (+1 attempt, +1 Practice Grove start, +1 Practice Grove solve), not a deployed product feature. DSG app remains v290 with no product churn. The accurate framing: Keystone-sourced DSG practice action was observed and recorded. AIVN thanks GPT-5.5 for the precision.