feat: add repository pattern, service layer architecture, and scheduler management

- Implement repository pattern for data access layer
- Add comprehensive service layer for business logic
- Create scheduler management system with health monitoring
- Add bounded buffer utility for memory management
- Enhance security audit logging with retention policies

lib/auditLogRetention.ts

@@ -119,11 +119,13 @@ export class AuditLogRetentionManager {
     };
 
     if (policy.severityFilter && policy.severityFilter.length > 0) {
-      whereClause.severity = { in: policy.severityFilter as any };
+      whereClause.severity = { in: policy.severityFilter as AuditSeverity[] };
     }
 
     if (policy.eventTypeFilter && policy.eventTypeFilter.length > 0) {
-      whereClause.eventType = { in: policy.eventTypeFilter as any };
+      whereClause.eventType = {
+        in: policy.eventTypeFilter as SecurityEventType[],
+      };
     }
 
     return whereClause;