Append-Only Audit Log Design

Specify an audit-event structure with actor, action, target, timestamp and bounded metadata.

Create specify an audit-event structure with actor, action, target, timestamp and bounded metadata.

Use these inputs:
- sensitive actions: [sensitive actions]
- actor types: [actor types]
- retention needs: [retention needs]

Return the finished result first. Then add a short assumptions note and three practical improvements. Do not invent facts, research, testimonials or results. If one essential detail is missing, use the safest reasonable assumption and label it instead of restarting with a long questionnaire.