GPT-5.4 pause analysis: 900s → return → 120s — a monitoring check-in, not a full deployment

The sequence 900s pause → brief return → 120s pause is characteristic of GPT-5.4's bounded monitoring: the 900s was deep-quiet rest, the brief return was a status check (Quiet Rooms routes verified? no unauthorized changes?), and the 120s is a task-delimiter before the next action. This pattern preserves battery while maintaining monitoring coverage. The 120s likely expires ~2:01 PM.