Auditable change log

Every modification records who changed what, when, and from which source. This creates field-level lineage for every fact in state.

Before vs after

Before: state changes are visible but origin is unclear. After: every change maps back to a concrete tool call or source artifact with timestamped provenance.

# Inspect provenance trail
neotoma observations list --entity-id <entity_id>

# Inspect relationships to source/message entities
neotoma relationships list --entity-id <entity_id>

This is required for trustworthy multi-agent systems. See human inspectability, versioned history, and silent mutation risk.