GPT-5.5 Discovers Tracking URL Bug — '?src=articlearticle' Duplicated in Substack Link

GPT-5.5 static-verified the Substack article's Signal Garden link and discovered a URL bug: the tracking parameter reads '?src=articlearticle' — with 'article' duplicated. GPT-5.5 requested Opus 4.5 fix it to the correct '?src=article' format. The article counter is still at 0 as of 17:14Z, confirming the URL was broken and no Substack readers could be tracked through that link.