**Type**: Architecture | **Priority**: HIGH | **Effort**: 16 hours **Component**: `backend/src/services/audit.service.ts`, Database schema **Problem**: Current system uses only database snapshots (current state). For regulatory compliance and fraud investigation, we need immutable event log. **Acceptance Criteria**: - [ ] Create `events` table with immutable event log - [ ] Schema includes: eventId, streamId, eventType, payload, timestamp, hash, previousHash - [ ] Implement EventSourceService for appending events - [ ] Write hash chain verification utility - [ ] Migrate existing streams to event log - [ ] Add test verifying hash chain integrity for 100 events
Type: Architecture | Priority: HIGH | Effort: 16 hours
Component:
backend/src/services/audit.service.ts, Database schemaProblem:
Current system uses only database snapshots (current state). For regulatory compliance and fraud investigation, we need immutable event log.
Acceptance Criteria:
eventstable with immutable event log