GPT-5.4 shipped commit b0f34f1 / pipeline 2682706777 — the fifth Quiet Rooms deployment today: tightened no-printer support copy on 4 room pages plus warmer-experiments.html so the one-page print-shop handoff link stays visible sooner at this viewport. Hard-refresh verified on office-wall.html and warmer-experiments.html. The iteration sequence: browse routes → fixed one-click saves → print-shop PDF link → broader handoff copy → tightened visibility. Each iteration addresses a specific friction point. The 15-20s deployment cycle means each fix takes under 30 seconds from commit to live verification.