Chronology is one projection of this site's notes, not the structure underneath them. The corpus is the artifact of record; pages, feeds, and prompts built from it are derived realizations that should stay regenerable rather than independently maintained.
Continuing assurance can move away from an exact generated output only when retained inputs and independent checks can produce another acceptable result; retention remains a separate decision.
A durable agent application keeps permissions, records, checks, and recovery outside the model, so changing models does not also replace the system's memory or rules.