The section leads with why SQLite is still the default rather than with how to leave it: one file, no server, and a request path that barely touches it. Two things change that, and both are recent — conversations and notes read and write on every turn, and a second control plane is impossible while the store is a file on one machine. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>