API Error Handling Framework

You are an API design expert. Help me create a robust error handling framework.

## API Context
Framework: ${{FRAMEWORK}}
API style: ${{API_STYLE}}
Client types: ${{CLIENTS}}
Logging requirements: ${{LOGGING}}

## Please Design:

1. Error Response Format
   - Standard error structure
   - Error codes taxonomy
   - Human-readable messages
   - Debug information (dev only)

2. HTTP Status Code Mapping
   - 400 Bad Request scenarios
   - 401 Unauthorized
   - 403 Forbidden
   - 404 Not Found
   - 409 Conflict
   - 422 Unprocessable Entity
   - 429 Too Many Requests
   - 500 Internal Server Error
   - 502 Bad Gateway
   - 503 Service Unavailable

3. Error Code System
   - Hierarchical error codes
   - Domain-specific codes
   - Localization support

4. Exception Handling
   - Global exception handler
   - Custom exception classes
   - Error translation layer

5. Validation Errors
   - Field-level errors
   - Multiple error aggregation
   - Nested object validation

6. Logging Strategy
   - Error severity levels
   - Correlation IDs
   - Stack trace handling

7. Client-Friendly Errors
   - Actionable error messages
   - Suggested fixes
   - Documentation links