GitLab CI/CD Pipeline Configuration

Create a comprehensive GitLab CI/CD pipeline for my project.

Project specifications:
- Project type: [application/library/infrastructure]
- Language/Framework: [specify]
- Testing requirements: [unit/integration/e2e]
- Deployment environments: [list environments]
- Runners: [shared/specific/tags]

Pipeline features needed:
1. Multi-stage pipeline (build, test, deploy)
2. Parallel job execution
3. Caching and artifacts
4. Environment-specific variables
5. Manual approval for production
6. Dynamic environments for merge requests
7. Container scanning and SAST
8. Release management
9. Rollback procedures
10. Notifications (Slack/email)

Include .gitlab-ci.yml with extends, anchors, and include statements for maintainability.