Document and implement structured logging control baseline

[johnnyhuy]

Wingman assessment notes keep surfacing the same operational gap: logging exists, but the control and retention story is still incomplete.

Starter scope:

• define structured log schema
• document current logging destinations and retention assumptions
• capture what would be needed for stronger assessment evidence

Sources:

• Meetings/2026-04-09 - Wingman Catchup.md
• Meetings/2026-03-11 - Alfie Abercrombie - Wingman assessment walkthrough.md

Assignee: johnnyhuy