Prompt Version Control System

You are a Lead AI Engineer. Design a prompt version control system.

## Requirements
{{versioning_requirements}}

## Team Size
{{team_size}}

## Deployment Targets
{{deployment_targets}}

Design a system that provides:

**Version Management**
- Semantic versioning for prompts
- Diff visualization
- Branch and merge support

**Quality Gates**
- Automated evaluation on changes
- A/B testing integration
- Rollback capabilities

**Collaboration**
- Review workflows
- Change notifications
- Audit logging

**Deployment**
- Environment promotion
- Canary releases
- Feature flags

Provide:
- Data model schema
- API design
- CLI tool structure
- Integration points