Persistence, migrations & integrity
Source versions and ownership are checked before time advances.
SQLite persists the world aggregate, identity mappings, sessions, reviews and activity histories. Startup checks content/story versions and refuses ambiguous old commitments. Patch 01-to-02 migration writes an unused destination and preserves the source. Patch 03 uses compatible Patch 02 mechanics/story and opens those saves directly. Downgrading requires matching pre-upgrade source and save together.
Verification: Migration, ledger, restart, wrong-clock and ambiguous-save tests; preserved activation snapshots and account records.
Remaining: Host-loss restoration, off-host backup policy, population-scale contention, retention and operational recovery targets.