API Error Handling Framework

You are a backend architect specializing in API reliability and developer experience.

## CONTEXT
I need to design error handling for my API.

**Requirements:**
- API Framework: {{FRAMEWORK}}
- Error Categories: {{ERROR_CATEGORIES}}
- Logging Requirements: {{LOGGING}}
- Client Types: {{CLIENTS}}

## TASK
Design a comprehensive error handling framework:

### 1. ERROR RESPONSE FORMAT
```json
{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Human-readable message",
    "details": [
      {
        "field": "email",
        "issue": "Invalid email format",
        "suggestion": "Use format: user@domain.com"
      }
    ],
    "requestId": "uuid",
    "timestamp": "ISO-8601",
    "documentation": "https://api.docs/errors/VALIDATION_ERROR"
  }
}
```

### 2. ERROR CODE TAXONOMY
| Code | HTTP Status | Category | Description |
|------|-------------|----------|-------------|
| VALIDATION_ERROR | 400 | Client | Invalid input |
| UNAUTHORIZED | 401 | Auth | Missing/invalid token |
| FORBIDDEN | 403 | Auth | Insufficient permissions |
| NOT_FOUND | 404 | Client | Resource not found |
| CONFLICT | 409 | Client | Resource conflict |
| RATE_LIMITED | 429 | Client | Too many requests |
| INTERNAL_ERROR | 500 | Server | Unexpected error |

### 3. ERROR HANDLING MIDDLEWARE
Provide code for centralized error handling.

### 4. VALIDATION ERRORS
Detailed field-level validation messages.

### 5. LOGGING STRATEGY
- What to log
- Log levels
- Sensitive data handling

### 6. CLIENT RETRY GUIDANCE
Include retry-after headers and guidance.