Updated MAC Log ledger policy

Property	Value
description	Updated MAC Docs to reflect MAC Log as a private canonical ledger.
version	0.74.0
type	Update
related	MAC Log, Repo Boundaries

• Updated the MAC Log product page to describe the private canonical ledger model.
• Updated MAC repo-boundary docs to separate private mac-log history from public mac-docs publishing.
• Updated repo-local MAC Docs context and sync guidance to copy only public-ready MAC Log records into MAC Docs.