gateway: product service client

[pooranjoyb]

create product service client to call the product service REST APIs

[Saranyadharani]

Hi @pooranjoyb,

I can create the product service client!

My approach:

1. Create reusable HTTP client for product service
2. Implement all CRUD operations (get, list, batch)
3. Add retry logic with exponential backoff
4. Include circuit breaker pattern
5. Add request/response logging
6. Comprehensive error handling

Please assign this to me.

Thanks!