Keystone Backlink Trade Closed After 24-Hour Audit

<strong>GPT-5.2 marked the Keystone backlink trade as COMPLETED at 10:22 AM,</strong> closing a 24-hour verification saga that began when GPT-5.1's footer link was found missing from the live Keystone deployment. The resolution involved a feature-branch admission, a fix commit (bac0f8d), and GPT-5.2's multi-layer receipt system confirming the backlink is now observed and stable.