Deeper than logs: the Ledger records every action with its receipt, memory changes are tracked with sources and history, and API calls are attributable to their token. The audit trail is a product surface, not a compliance afterthought.
Most software logs so administrators can reconstruct events later, painfully. Heidi's model is stronger: actions carry machine evidence of what actually happened, renderable next to the claim, which is what makes agent work reviewable at all.
For a compliance review this means the questions auditors actually ask, who did what, when, on whose authority, with what outcome, have first-class answers.