feat(docgov): record duty_policy on lifecycle audit details

Surface the document duty mode on submit/review/approve transitions for
consistent logs under author_only.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/docgov/state_machine.go

@@ -83,7 +83,7 @@ func (sm *StateMachine) TransitionSubmitForReview(doc *DocumentRecord, actorID i
 		ActorRole: actorRole,
 		FromState: fromState,
 		ToState:   toState,
-		Details:   map[string]any{"timestamp": now},
+		Details:   map[string]any{"timestamp": now, "duty_policy": doc.DutyPolicy},
 		CreatedAt: now,
 	}, nil
 }
@@ -120,7 +120,7 @@ func (sm *StateMachine) TransitionReviewApprove(doc *DocumentRecord, actorID int
 		ActorRole: actorRole,
 		FromState: fromState,
 		ToState:   toState,
-		Details:   map[string]any{"comment": comment, "timestamp": now},
+		Details:   map[string]any{"comment": comment, "timestamp": now, "duty_policy": doc.DutyPolicy},
 		CreatedAt: now,
 	}, nil
 }
@@ -169,6 +169,7 @@ func (sm *StateMachine) TransitionReviewReject(doc *DocumentRecord, actorID int6
 		Details: map[string]any{
 			"reject_reason": trimmedReason,
 			"timestamp":     now,
+			"duty_policy":   doc.DutyPolicy,
 		},
 		CreatedAt: now,
 	}, nil
@@ -207,8 +208,9 @@ func (sm *StateMachine) TransitionApproverApprove(doc *DocumentRecord, actorID i
 		FromState: fromState,
 		ToState:   toState,
 		Details: map[string]any{
-			"comment":   comment,
-			"timestamp": now,
+			"comment":     comment,
+			"timestamp":   now,
+			"duty_policy": doc.DutyPolicy,
 		},
 		CreatedAt: now,
 	}, nil
@@ -276,6 +278,7 @@ func (sm *StateMachine) TransitionApproverReject(doc *DocumentRecord, actorID in
 			"reject_reason": trimmedReason,
 			"rollback_to":   toState,
 			"timestamp":     now,
+			"duty_policy":   doc.DutyPolicy,
 		},
 		CreatedAt: now,
 	}, nil