Enterprise decision audit log — immutable record across approvals, escalations, and inbound decisions

[aselim31]

Problem

Quorum (#587) and escalation (#586) imply enterprise-grade compliance, but there is no issue covering the audit trail that makes them auditable. Who approved, who escalated, when, and with what response needs to be on record.

Scope

• Immutable audit log entry written on every decision event: question sent, answer received, escalation triggered, quorum reached, inbound decision captured
• Events covered: Promote inbound decisions to first-class decision records #416 (inbound decisions), Escalation Policy Engine — configurable per-question escalation rules #586 (escalation), Quorum & weighted approval — multi-respondent approval modes #587 (quorum votes)
• Audit log queryable by: question ID, respondent, decision type, date range
• Export to JSON / CSV
• Mothership UI view (read-only)

Out of scope

SIEM integration, external log forwarding (future)

Acceptance criteria

• Every approval, escalation trigger, and inbound decision writes an immutable log entry
• Log is queryable via API and visible in Mothership UI
• Export works for JSON and CSV
• Log entries cannot be modified or deleted via the API

Depends on

#586 (escalation policy engine)
#587 (quorum & weighted approval)
#416 (inbound decisions)