feat: add secret rotation service for database credentials and API keys (closes #79)

src/lib.rs

@@ -55,6 +55,21 @@ pub mod backup;
 // exponential-backoff retry and verified via BLS signature checks.
 pub mod webhook;
 
+// Runtime configuration auditing and drift detection.
+// Compares approved baselines with runtime snapshots to detect
+// unexpected changes during blue-green or canary rollout gates.
+pub mod config_audit;
+
+// Multi-region replication and disaster-recovery primitives (issue #91).
+// Dependency-free topology management with failover planning,
+// canary analysis, and DR-test reporting.
+pub mod replication;
+
+// Secret rotation service for database credentials and API keys (issue #79).
+// Versioned credential store with scheduled expiry, dual-ended grace windows,
+// and atomic rotation that keeps old credentials live for in-flight requests.
+pub mod secret_rotation;
+
 // --- ERROR CODES ---
 
 #[contracterror]