902e9d8dfb
- Implement API version management middleware - Add version lifecycle management (dev/stable/maintenance/deprecated/sunset) - Add deprecation warning headers (X-API-Deprecated, X-API-Sunset-Date) - Add version tracking headers (X-API-Version) - Handle sunset versions with 410 Gone response - Comprehensive API versioning documentation - Include migration guide and best practices - Support gradual version rollout Phase 4 Task 44/68 completed