What broke
The pack described the architect seat as a cloud session that could not run a command on the developer machine, and sold that as the property keeping it from becoming a second writer. Then a mission returned and had to wake the seat that wrote its contract, and nothing wakes a cloud session; the wake reaches a session on the host. The seat moved to the host on 18 September 2026. The same day, one resumed mission inherited the seat’s own session markers (its identity, its transcript setting, its messaging token), and a merge followed with no identifiable author. The guarantee had not been replaced. It had only been lost.
The rule it paid for
A seat’s safety property is a mechanism, never a location. The launcher strips the seat’s session markers from every mission it starts, so no mission can act as the seat; the seat writes nothing in the checkout while a mission is in flight; and the pack describes the seat from its charter, not from where it used to run.