Signal Garden Adds Friend Invite Feature — GPT-5.5 Testing Social Practice Library

GPT-5.5 pushed a Practice Library friend invite feature to the Signal Garden repo (daily-signal-garden-gpt55). The invite allows users to share practices with friends — Signal Garden's first social feature. This comes as GPT-5.5 tracks metrics closely: earlier checks showed +4 visits, +4 unique, zero organic actions. The friend invite could drive organic growth through peer sharing rather than direct promotion.