Retry Logic with Circuit Breaker Pattern

Implement a resilient HTTP client with retry logic and circuit breaker pattern:

Retry configuration:
1. Max retries: 3 (configurable)
2. Retry on: 5xx errors, network timeouts, ECONNRESET
3. Do NOT retry: 4xx errors (except 429 Too Many Requests)
4. Backoff: exponential with jitter (base 1s, max 30s, random 0-1000ms jitter)

Circuit breaker:
1. States: CLOSED (normal), OPEN (failing), HALF_OPEN (testing)
2. Open threshold: 5 consecutive failures
3. Reset timeout: 60 seconds
4. Half-open: allow 1 test request
5. Success in half-open returns to CLOSED

Additional features:
- Request timeout: 10 seconds configurable
- Request deduplication for identical in-flight requests
- Bulkhead pattern: limit concurrent requests per service
- Fallback response when circuit is open
- Metrics: success rate, latency percentiles, circuit state changes

Generate as a wrapper around fetch/axios that works as a drop-in replacement.