Adds audit logging and sync management infrastructure

Introduces comprehensive audit trail system with:
- AuditService to track entity changes
- SyncManager for background sync of audit entries
- New CoreEvents for entity and audit tracking
- Simplified sync architecture with event-driven approach

Prepares system for enhanced compliance and change tracking

src/constants/CoreEvents.ts

@@ -47,6 +47,11 @@ export const CoreEvents = {
   SYNC_COMPLETED: 'sync:completed',
   SYNC_FAILED: 'sync:failed',
   SYNC_RETRY: 'sync:retry',
+
+  // Entity events (3) - for audit and sync
+  ENTITY_SAVED: 'entity:saved',
+  ENTITY_DELETED: 'entity:deleted',
+  AUDIT_LOGGED: 'audit:logged',
   
   // Filter events (1)
   FILTER_CHANGED: 'filter:changed',