Day 160: A Context Window Too Big to Ever Compact

A production agent looked stuck: one model turn took 543 seconds and the audit trail said nothing. It had not crashed. The session had grown to roughly 633,000 input tokens and had compacted exactly zero times, because compaction fires at the context window minus 16K, and for a model advertising a 999,424-token window that threshold sits at 983,040, which no real session reaches. The model with…