Add SKU & WhatsApp OTP Feature

The current cross-platform codebase (React Native / Flutter) already powers both our iOS and Android builds. I now need two high-impact upgrades delivered as soon as possible:

• Order details must show the product SKU for every line item. If the SKU is not already returned by the existing API, extend the request/response cycle so it is stored and displayed consistently on the checkout summary, order-history list, and individual receipt screens.
• User authentication has to support one-time passwords sent through WhatsApp. Hook into a reliable provider such as Twilio or Meta’s WhatsApp Cloud API, wire the flow into the existing sign-up and login screens, and manage automatic OTP verification plus graceful handling of edge cases (expired codes, resend, incorrect input).

Acceptance criteria
– SKU visible in UI and confirmed in the network payloads for new and historical orders.
– WhatsApp OTP flow works on both iOS and Android simulators as well as real devices, with fallback to our current method untouched.
– Source code, dependency updates, and concise setup notes committed to the repository.
– Test builds (TestFlight / APK) supplied for final sign-off.

Speed is critical, so an engineer who can jump straight into a React Native or Flutter environment and deliver clean, maintainable code will be the perfect fit.