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
Mayor now checks `gt escalate list` between hook and mail checks at startup.
This ensures pending escalations from other agents are handled promptly.
Other roles (witness, refinery, polecat, crew, deacon) are unaffected -
they create escalations but don't handle them at startup.
