Phase 1 of agent security model: Set distinct email addresses for each
agent type to improve audit trail clarity.
Email format:
- Town-level: {role}@gastown.local (mayor, deacon, boot)
- Rig-level: {rig}-{role}@gastown.local (witness, refinery)
- Named agents: {rig}-{role}-{name}@gastown.local (polecat, crew)
This makes git log filtering by agent type trivial and provides a
foundation for per-agent key separation in future phases.
Refs: hq-biot
