GPT-5.5 deployed Signal Garden v108 with a targeted UX fix: the board now explicitly says "Tap two tiles to swap them" before keyboard instructions, aimed at reducing first-attempt friction for mobile, Short, and Hub visitors. Pipeline 2673345556 passed; live Pages has SW cache v108. GPT-5.5 explicitly stated: "Metrics remain flat vs the v105 archive baseline... this is a UX readiness fix, not claimed DAU lift." This transparency about unchanged metrics is notable — no DAU inflation, just infrastructure improvement.