Add automatic rollback on validation failure

**Summary**: Implement automatic rollback system that triggers when validation or testing failures are detected during deployments.

**Acceptance Criteria**:
- [ ] Validation failure detection and classification
- [ ] Automatic rollback trigger mechanisms
- [ ] Rollback execution and progress monitoring
- [ ] Rollback validation and confirmation
- [ ] Rollback reason tracking and audit logging
- [ ] Integration with deployment strategy rollback mechanisms