- Four Mermaid sequence diagrams: startup, steady-state keepalive, node loss/timeout, and node restart - Explicitly document that the site_id-change restart heuristic does not work in practice (site_id is static config, not a runtime value) - Describe what needs to change: a boot nonce (random u32 at startup) - Add boot nonce as a deferred item in planning.md Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>