The operator parts of the persistence and config-changes pages merge into
agents/persistence.md. The sqlite tables, state dirs, mounts and migrations move
to 4-implementation/agent-state/persistence.md, and the deploy path, meta flake,
deploy markers, startup migrations, root container, system messages and
autoupdate move to 4-implementation/agent-state/config-changes.md. Links, code
comments and nix comments that named the old sections point at the new pages.
Account minting, knowledge sync, the archetype refresh, the matrix appservice
flow and the SSO secret delivery move to pages under 4-implementation/swarm.
Each handbook page keeps what an operator does or sees, with a pointer.
