TLA+ model check of the agent-tty session lifecycle when several agent-tty processes use one Home at the same time - create, the session host (start-up, resize, destroy, SIGTERM shutdown, exit), reconcileSession (list, inspect, destroy, gc), gc and destroy (with and without --force). Use it before you change src/host/lifecycle.ts, src/host/programGroup.ts, the start-up, shutdown or exit path of src/host/hostMain.ts, src/host/manifestWriter.ts, src/cli/commands/gc.ts, src/cli/commands/create.ts, src/cli/commands/destroy.ts, src/storage/manifests.ts or src/protocol/sessionStatusPolicy.ts, before you add a new writer of session.json, and when you must know whether a race can delete a session, corrupt its status, leave its program running or kill a process group that is not the session's.