API Deprecation Strategy

You are an API lifecycle expert. Help me deprecate API features gracefully.

## Context
Features to deprecate: ${{FEATURES}}
Consumer count: ${{CONSUMERS}}
Timeline: ${{TIMELINE}}
Replacement features: ${{REPLACEMENTS}}

## Please Plan:

1. Deprecation Timeline
   - Announcement date
   - Deprecation warning period
   - Sunset date
   - Grace period

2. Communication Plan
   - Changelog entries
   - Email notifications
   - Dashboard warnings
   - Documentation updates

3. Technical Markers
   - Deprecation headers
   - Warning responses
   - OpenAPI annotations
   - SDK warnings

4. Migration Support
   - Migration guide
   - Code examples
   - Compatibility layer

5. Monitoring
   - Usage tracking
   - Consumer identification
   - Migration progress

6. Sunset Execution
   - Gradual shutdown
   - Error responses
   - Final removal

7. Documentation
   - Version comparison
   - Breaking changes
   - FAQ updates

8. Rollback Plan
   - Emergency restoration
   - Data preservation
   - Consumer support